Past Exam 2 Pharmaceutics

Why People question vaccines: Timing

1. Onset of neurological disorders commonly occur in 1st and 2nd year of a child's life- exact same time a majority of the childhood vaccines are given

Evaluation of the Comfort of Alphagan P Compared with Alphagan in Irritated Eyes

1. 2 wk, single-center masked, crossover study 2. >/= 18 yo with normal ocular health, bilateral glaucoma, or ocular hypertension 3. N=20 patients who experienced at least a 3/4 on ocular discomfort scale when exposed to controlled adverse environment up to 90 mins 4. Drop preference after cross-over dosing on days 11 and 15

Onpratto what is the function of each component?

1. 2.1 mg Patisiran (double stranded RNA siRNA silences the expression of ATTR) 2. Lipids for encapsulation of the SiRNA into liposomes. -Protects the siRNA into liposomes -protect SiRNA - delivers siRNA into cells 3. Potassium phosphate and sodium chloride to adjust pH and isotonicity of parenteral formulation

Herd Immunity

1. A large enough fraction of the population is immunized or has protective immunity and therefore the disease cannot spread easily to those that are not protected because they cannot or did not get the vaccine -Threshold % is unique for the disease a. Diptheria- 85% b. Measles- 83%-94% c. Mumps- 75%-86% d. Pertussis- 92-94% e. Polio- 80-86% f. Rubella- 80-85% g. Smallpox- 83-85%

Restasis Opthalmic Emulsion

1. API= cyclosporine 0.5 mg/mL 2. Indicated to increase tear production in patients whose tear production is presumed to be suppressed due to ocular inflammation associated with keratoconjunctivitis sicca 3. Water in castor oil and polysorbate 80, different indications- special delivery system- bad water solubility- put into an emulsion- water + oil mixture and surfactant

FDA approved adjuvants

1. ASO4 -Adjuvant system #4 (AS04) - GSK -Only in Cervarix which has been taken off the US market due to safety concerns 2. ASO3 -D,L-alpha-tocopherol (vitamin E), Squalene and An emulsifier, polysorbate 80 (Tween 80) -Forms an emulsion -Only approved in pandemic H5N1 influenza vaccine (GSK) 3. MF59 -Only in Fluad Novartis influenza vaccine for 65+ individuals -Squalene, Tween 80, Span 85- forms an emulsion 4. CpG 1018 -Synthetic DNA- TLR9 agonists -In Heplisav-B hepatitis B vaccine 5. ASO1B -Liposomal MPL (Avanti Lipids) with Qs-12 -QS-21 is a sterol based isolated from soap bark tree (Quillaja saponaria) -Induced in Shingrix (Shingles) and Mosquirix (Maleria; pre clinical)

Cellular Scale: Transvascular Transport

1. Absorbed drugs are delivered via the systemic blood circulation 2. The drugs must escape the microcirculation of each organ, enter the interstitial space, and reach individual cells 3. Drugs move through a. The plasma b. The cell c. The interstitial fluid Examples of drug moving from blood to organ: Cellular or Molecular scale -Function of drug to cross? -tight junction prevent drugs from crossing

Example of Third Order Passive Targeting

1. Acid sensitive polymeric nanoparticles for vaccine delivery -One phagocyte can pick up particles larger than 100 nm 2. Third order targeting -Delivery specifically to the internal or intracellular site of a cell (specific cellular component) 3. Responds to PH as it enters the cell via endocytes, nanoparticles dissolves at lower pH and released only upon internalization into the cell

Johnson and Johnson (Janssen) Covid 19 vaccine

1. AdVac technology uses a nonreplicating version of the adenovirus type 26 (Ad26) 2. Normal refrigeration 3. Trials were performed in the US and South Africa, with single vaccine (prime only) -66% overall vaccine efficacy -85% effective in preventing severe disease (one shot)

Flu Ad- MF59 Adjuvanted Vaccine (recommended for elderly)

1. Adjuvanted vaccine that is recommended for the elderly 2. 0.5 mL dose (IM) MF59- adjuvant 3. FLUAD dose not contain a preservative 4. MF59 is made in Holly Spring NC 5. does not contain latex, but the tip of the cap of the prefilled syringe contains latex, which may cause an allergic reaction 6. increases the residence time via an emulsion adjuvant system with oil stabilizers

Barriers in Nucleic Acid Delivery

1. Administration and circulation a. clearance by kidney b. phagocytic uptake c. Immune recognition d. Aggregation with serum proteins e. Degradation by endonucleases 2. Extravasation and accumulation a. transport across the capillary cell wall 3. Distribution and diffusion a. Obstruction by a dense network of extracellular matrix proteins b. phagocytic uptake 4. Cellular entry and trafficking (intracellular barriers) a. cellular entry b. endosomal trapping c. endocytic recycling d. Lysosomal degradation e. Crossing the nuclear membrane easier to deliver SiRNA and RNA then DNA, plasmid DNA need to get into nucleus; DNA needs to overcome nuclear membrane Endosomal escape and nuclear membrane are part of intracellular barriers to nucleic acid delivery Main extracellular a. Clearance by kidneys and liver b. aggregation c. phagocytic clearance

What are the advantages and disadvantages of systemic drug delivery for treatment of ophthalmic disease?

1. Advantages: -can deliver therapeutic concentration of drug delivered to the back of the eye -Easy administration may promote good patient adherence compared to other dosage forms 2. Disadvantages -difficult to selectively target ocular tissues -may need high doses of oral medication to achieve therapeutic concentrations -systemic side effects and toxicity

General safety considerations

1. All ophthalmic products must pass a USP sterility test -Pseudomonas aeruginosa is the main cause of blindness from contaminated ophthalmics 2. Methods of sterilization depends on product a. Sterile membrane filtration under aseptic conditions but not suitable for suspension b. Sterilization by autoclaving in the final container but not suitable for heat labile drugs and plastic containers c. Gas, as ethylene oxide or Ionizing radiations as gamma ray

Alphagan Reformulation

1. Alphagan (discontinued) -Each mL of ALPHAGAN contains: API: brimonidine tartrate 0.5 % (5 mg/ mL) Preservative: benzalkonium chloride (0.05 mg) Inactive ingredients: citric acid; PVA; sodium chloride; sodium citrate; hydrochloric acid and/or sodium hydroxide to adjust pH 2. ALPHAGAN P Each mL of ALPHAGAN P contains: API: brimonidine tartrate 0.1% (1.0 mg/mL) or 0.15% (1.5 mg/mL) Preservative: PURITE 0.005% (0.05 mg/mL) Inactive ingredients: sodium carboxymethylcellulose; sodium borate; boric acid; sodium chloride; potassium chloride; calcium chloride; magnesium chloride; hydrochloric acid; and/or sodium hydroxide to adjust pH -added viscosifying agent to decrease amount of drug

Cell Membrane: Cellular Space

1. Fluid mosaic model -Globular transmembrane proteins are embedded in a dynamic fluid, lipid bilayer a. Facilitate transfer of polar molecules and charged ions b. Pores about 10-70 nm in size -Water, ions, and dissolved solute transport

Adjuvant Alum

1. Alum, chemically speaking is potassium alum 2. Alum is also commonly referred to as two aluminum salts -Aluminum hydroxide -Aluminum phosphate 3. It was discovered in 1926 and used for > 50 years 4. Most adjuvant Childhood: Tetanus, diphtheria, pertussis, and poliomyelitis vaccines VLP: Hepatitis A and hepatitis B virus Special populations: Anthrax 4. Does not have a conferred mechanism of action but is though to create a depot to release antigen

Why People question vaccines: Isolated Groups

1. Anecdotal evidence of reduced autism in isolated populations -Unscientific reports that autism is rarer in the Amish community and other non-vaccinated groups. a. Amish genes may differ from those in the general community b. The Amish community have low exposures to many other potential hazards (for example, pesticides, and plastics) c. Increasingly, the Amish do receive at least some vaccinations

Onpratto- Lipid nanoparticles deliver siRNA

1. Approved in 2018 2. Indication: hereditart ATTR amyloidosis -TTR= transthyretin -ATTR amyloidosis can lead to the dysfunction of many organs 3. Route of administration: intravenous infusion 4. Parenteral drug product: should be inspected visually for particulate matter and discoloration prior to administration 5. Onpratto decreases the production of ATTR through RNA interference

GIVLAARI

1. Approved in 2019 2. Indication: Acute Hepatic Porphyria (AHP_ 3. Route of administration: subcutaneous injection 4. Prior to administration it should be inspected visually for particulate matter and discoloration 5. Acute hepatic porphyria (AHP): AHP is a rare genetic disease characterized by potentially life threatening attacks and, for some people, chronic debilitating symptoms that negatively impact daily functioning and quality of life

Givlaari

1. Approved in 2019 2. Indication: Acute Hepatic Porphyria- rare genetic disease characterized by life threatening attacks, for some people, chronic debilitating symptoms that negatively impact daily functioning and quality of life 3. Route of administration: Subcutaneous injection 4. Prior to administration it should be visually inspected for particulates matter and discoloration

Anatomy of the Eye

1. Aqueous compartment- in front of the lens- anterior chamber 2. Posterior compartment- behind the lens- vitreous compartment

Anatomy of the Eye

1. Aqueous humor flow: ciliary body -> posterior chamber -> anterior chamber 2. iris is responsible for contraction and expansion causing dilation and constriction 3. Glaucoma- build of fluid due to blockage of trabecular meshwork

Example of Second Order Active Targeting

1. BIND-014 (PSMA-targeted docetaxel) is a PLGA nanoparticle formulation that is a ACCURINS nanoparticle in Phase II clinical trials -PLGA core (red) loaded with docetaxel -PEGylation (grey) -Prostate-specifice membrane antigen (PSMA) antibody for targeting (blue) 2. Second order targeting -Specific delivery of a drug to a special cell type, such as tumor cell, and not to normal cells (antibody is an example)

BCG Vaccine in Populations- illustrates vaccines are not 100%

1. Bacillus Calmette Guerin (BCG) is a vaccine against tuberculosis that is prepared from a strain of the attenuated live bacteria of bovine tuberculosis bacillus -High level of variance with race 2. This is an extreme example of variance in vaccine efficacy. More commonly applied vaccines are not this variant

More on Preservatives

1. Benzalkonium chloride- most common ophthalmic preservative 2. Purite (SOC)- antimicrobial free radicals, degrades in presence of UV light 3. Sodium perborate (NaBO3)- produces hydrogen peroxide, degrades methyl and propyl hydroxybenzoate 4. Alcohol substitutes (phenylethanol, chlorobutanol of pH 5-6) 5. sofZia (zinc chloride, boric acid, propylene glycol, sorbitol) 6. Polyquad (polyquaternium-1)- BAK derivative that dose not bind contacts 7. polyheamethylene biguanide- used in contact lens cleaning solutions 8. thimerosal- may cause allergic reactions, rarely used

Pfizer and Moderna lipid nanoparticles (LNPs)

1. Cationic and neutral lipids can be used to complex anionic DNA 2. These are not necessarily liposomes, they are lipid complexes 3. Advantages: Charge neutralization and size can facilitate immune cell uptake 4. Challenges: -Nucleotides potentially available for degradation -Pre-existing or induced immunity against PEG and phosphorylcholine -Cationic lipids can adduct host DNA and have toxicity concerns -Often requires very low storage temperatures* 5. 95% at preventing symptomatic COVID infection in patients who were part of the clinical trial 6. FDA approved December 11, 2020 and for emergency use 7. 0 prime and boost (day 21) 8. Cholesterol make nanoparticle more stable and make more rigid

Composition of Onpratto

1. Cationic/ionizavle lipids encapsulate negatively charged siRNA through electrostatic interactions 2. PEGylation of lipid nanoparticles allow longer circulation in the bloodstream 3. siRNA is chemically modified to enhance stability

Lucentis

1. Choroidal neovascularization can result from an overexpression of vascular endothelial growth factor (VEGF)- common in macular degeneration 2. Lucentis a. Ranibizumab lacks an Fc region which promotes rapid systemic clearance b. Rapid clearance is advantageous if drug drains into systemic circulation c. MW= 48 kDA d. Potent VEGF inhibition e. Vitreous t1/2= 9 days

Routes of Administration that can be local

1. Colonic- advanced delivery systems 2. Buccal- Solutions, suspensions, lozenges 3. Rectal- Suppositories, ointments, creams, solutions, suspensions, foams 4. Vaginal- suppositories, creams, gels, tablet rings 5. Topical (skin)- Ointments, creams, gels, lotions, aerosols, powders 6. Intranasal- solutions, suspensions, or aerosols 7. Pulmonary- Aerosolized solutions, suspensions, or powders 8. Opthalmic- solutions, suspensions, ointments, gels, inserts, injections 9. Otic- solutions, suspensions, ointments

Take Home Points

1. For drugs to be delivered they have to pass through several barriers including cells and body fluids 2. Because sometimes a better drug efficacy and specificity is needed, drugs can be formulated and sometimes these formulations or injection of these formulations result in local over systemic delivery 3. Several concepts are used to deliver drugs in a more precise manner. Concepts like controlled release, targeting, asymmetric delivery, and timed release can help accomplish more precise delivery 4. Where and how drug therapies are targeted are named 1st-3rd order depending on how they are targeted they can be actively or passively targeted

Systemic Delivery

1. Common routes of administration a. Always systemic -Intravenous b. Most often systemic -Oral, stomach c. Often systemic -Transdermal, Rectal d. Sometimes systemic -Buccal, Vaginal, Nasal 2. Drug concentrations is roughly equal in the blood a. At site of action, the drug concentration is roughly the same as elsewhere in unaffected tissue b. Can lead to toxicity concerns i. When high levels of drug are needed to be transported to site of action -A lot of drug at site of action means a lot of drug off site* ii. When low levels of a highly potent are needed at site of action - A little of a highly potent drug at site of action means a little of a highly potent drug off-site 3. Can make controlling drug concentrations straightforward (easy to administer and measure) 4. Something injected here will ideally go through the entire body, but must go through distinct organ level processes (frequently pass through organs are different) 5. Drugs can be delivered at these area, for affect through the body.

Why are preservatives included in multiple-dose solutions and not single-dose solutions?

1. Could hit top of the bottle with eyelid with bacterial contamination with rest of contents, so when the patient reuses the multi-dose solution, they would be introducing bacteria into the eye 2. Single dose: you only use once, so even if you contaminate the dropper you won't use it

Anti parallel double helix formation can happen between:

1. DNA-DNA 2. DNA-RNA 3. RNA-RNA 4. If we consider one strand as the sense strand, then the other strand will be the "antisense strand" This forms the theory of antisense DNA therapy of RNA interference (RNAi) therapy

Lymphoseek

1. Dextran with 2 functionalities: mannose and radio-ligand -Mannose is upregulated by macrophages and dendritic cells -When injected at cancer site will traffic to the local lymph nodes where the cancer drains for surgeon to remove 2. Mannose targets macrophages and dendritic cells 3. 99mTC (Technetium) is a radioactive isotope to image to nodes

Common Indications of Ophthalmic Drugs

1. Diagnostic and Procedural a. Anesthetics b. Miotics c. Mydriatics d. irrigating solutions e. Imaging agents f. mAbs and phototherapy for age related macular degeneration 2. Glaucoma a. Alpha 2 adrenergic agonists b. Beta blockers c. Carbonic acid anhydrase inhibitors d. Cholinergic drugs e. Prostaglandin analogues 3. Infection a. Antibiotics b. Antivirals c. Antifungals 4. Allergic and Inflammatory -Antihistamines -Anti-inflammatory -Corticosteroids -Mast cells stabilizers -Vasoconstrictors 5. Dry Eye -Astringents -Lubricants

Effective Cold Chain in a Pharmacy

1. Do -Dedicate fridge -Reliable electric supply -50% full maximum storage -Defrost and calibrate regularly -Have back up storage 2. Don't -Store food in the fridge/freezer -Store medical specimens in the same fridge/freezer -Have direct sunlight or heat source -Do not store in fridge/freezer door -Store away from fridge/freezer walls

Influenza Vaccine and GBS

1. Each influenza vaccine with virus also has a reported side effects of GBS (neuromuscular and muscle lock for 9 months to 1 year) 2. Sustained immune activation is thought to be linked to Guillain Barre syndrome in influenza syndrome 3. GBS is linked to influenza infection and listed as a precaution by the CDC on relevant package inserts 4. Largest observed incidence is 8.8 cases per million recipients (1976 flu season)

Visudyne (Verteporfin for injection)

1. Each mL of reconstituted Visudyne contains: API: verteporfin 2 mg Inactive ingredients: ascorbyl palmitate, butylated hydroxytoluene, dimyristoylphosphatidylcholine, egg phosphatidylglycerol, and lactose 2. Photosensitive drug injected IV as liposomal preparation 3. Binds to circulating lipoproteins (LDL) and concentrates as LDL receptors in the endothelium of the choroid neovasculature and RPE (Verteporfin for injection)

Topical Delivery: Corneal Anatomy

1. Epithelium -Lipophilic -Low porosity/high tortuosity -Greatest barrier to penetration 2. Stroma -90% of thickness of cornea -Acellular -Hydrophilic -High porosity/low tortuosity 3. Endothelium -One cell layer thick -Lipophilic

List 3 layers of the cornea

1. Epithelium: lipophilic, low porosity/ high tortuosity, greatest barrier to penetration 2. Stroma: 90% of thickness of cornea, acellular, hydrophilic, high porosity/low tortuosity 3. Endothelium: one cell layer thick, lipophilic

Dry Eye

1. Evaporation of lacrimal fluid resulting in gritty or itchy feeling in eyes- solutions, suspensions, emulsions, ocular inserts

Ophthalmic Drug Packaging

1. Eye drops are packaged almost entirely in a plastic dropper bottles a. Convenience b. Decreased contamination potential c. Lower weight; lower cost 2. Disadvantages a. Adsorption or permeation of some drugs b. Weight loss by water vapor transmission c. Evaporation of volatile preservatives such as chlorobutanol d. Translucent

Ocular Gene Therapy

1. Eye has several properties that may make it very amenable to gene therapy delivery -Localized delivery possible -Small amount of vector needed -Can keep vector system in contact with target tissue for prolonged time -Limited exposure to systemic circulation -Immune privilege 2. Increasing interest/effort in gene delivery to the eye 3. Has potential to selectively deliver genes and drugs to ocular tissues for the treatment of both hereditary and acquired diseases 4. Regulatable promoter system offer the potential to do a single administration of a gene therapy vector and then control gene expression by administration of a safe oral drug

Radioimmunotherapy

1. FDA approved 2002- Ibritumomab tiuxetan (Zevalin)- monoclonal antibody anti-CD20 conjugated to a molecule that chelates Yttrium-90 2. FDA approved 2003- Iodine 131 tositumomab (Bexxar)- links a molecule containing Iodine-131 to the monoclonal antibody anti-CD20

Take Home Points

1. FDA approved vaccines are subunits, VLP, inactivated, and live-attenuated, which all have different levels of safety 2. Alum is used in subunit vaccines as are other FDA approved adjuvants 3. Herd immunity confers protection of an entire population and protects those that are immunized and those that are not 4. There are several concerns with vaccines related to questionable scientific publications, concerns with preservatives and antigen load, and anecdotal evidence. These concerns have been shown scientifically not to be accurate; however, concerns still persist, perhaps because of the timing of vaccines and neuro-development. Vaccine formulations have been altered over time to help address these concerns.

Topical Delivery Systems more

1. Gellable drops (e.g Timoptic XE) -liquid which forms gel upon contact with eye -increases residence in eye which increases bioavailability and can provide sustained release 2. Inserts (e.g Ocusert- pilocarpine) -increases residence in eye which increases bioavailability and can provide sustained release -low patient acceptance (irritating; difficult to administer) 3. Soft contact lenses -provides controlled release into tear film

Antigenic Drift

1. Generally, each year there is an antigenic drift wherein most of the antibodies generated by the influenza vaccine for the previous year are ineffective against this year's influenza -Specifically, the hemagglutin (H) proteins that help bind the virus to the cell

Attenuated Pathogen

1. Genetically alter original pathogen so it is non-infective 2. Will not cause significant infection - Vaccination with attenuated pathogen provides protection against pathogenic pathogen 3. Protective immunity through attenuated organism with elements knocked out that result in reduced pathogenicity (e.g the dark green spikes allow for infection and absence of them prevents infection) Examples a. Measles b. Polio (Sabin) c. Rotavirus d. Varicella zoster (Chicken pox) e. Yellow fever f. Influenza (nasal)

Efficacy of Hepatitis B Vaccine

1. Given 3 times 1-4 months apart 2. Most vaccines have a high efficacy across most populations

Herd immunity

1. Herd immunity helps to protect us all -Subset of population cannot get vaccinated 2. Even if you are vaccinated, you can still get sick -Herd immunity can greatly reduce incidence of vaccinated and unvaccinated people from getting sick -Vaccines are not 100%- Just like drugs have different effects on different people, vaccines do as well

Permeability of Molecules through Cell membranes

1. High permeability across lipid layers -Gases (O2, N2, CO2) 2. Lower permeability across lipid layers -Smaller polar solutes (e.g urea, glucose, amino acids) 3. Virtually impermeable -Ions 4. Permeability proportional to partition coefficients -Partition coefficient is solubility of molecule in organic solvents compared to water (octanol/water)

Routes that can be Systemic

1. IV is always systemic- 100% bioavailable 2. SubQ 3. Transdermal 4. Oral 5. Inhalation 6. Buccal 7. Nasal

Systemic or Local?

1. Immune therapies -Vaccines -Applied locally, but activate cells throughout the entire body -im or sc injection 2. Targeted therapies -Some are delivered systemically, but targeted to enhance uptake in certain regions, although the drug is systemic (example: monoclonal antibody inkected IV but activity is on a tumor site)

DNA and RNA vaccines

1. In 1990 mRNA and DNA was injected IM and a local production of protein was observed as well as induction of immune response 2. On a molar basis mRNA has comparable response to DNA 3. Illustrated good pre-clinical activity against both infectious diseases and cancer Advantages of RNA vaccines over DNA -DNA could potentially integrate into host genome -DNA must go into the nucleus opposed to mRNA which can have influence in the cytosol - (+/-) Rna antigen expression can be shorter time frame than DNA expression -Both Pfizer and Moderna COVID-19 vaccine formulations are lipid nanoparticles with mRNA

Why do People question the vaccine: MMR Vaccine

1. In 1998 Andrew Wakefield published a paper in Lancet -Suggested a possible link with the MMR vaccine, but concluded -"We did not prove an association between measles, mumps, and rubella vaccine and the syndrome described" -Subsequent studies failed to reproduce his findings 2. Quick points on Wakefield -10 of Wakefield's 12 coauthors have retracted their work from his papers -The Lancet fully retracted the paper in 2010 -UK medical license was removed for acting dishonestly and irresponsibly -Profited through start ups, people suing vaccine suppliers, and other ventures discrediting vaccines 3. How has this impacted vaccine formulations? -It has brought into question antigen load and use of thiomersal -Since the early 1980's antigen load has decreased > 97% of what it was earlier

Hannah Poling Case (similar to Bank, Mojabi, and Moller)

1. In 2008, the government conceded one case concerning a child with an autism like outcome due in part to a vaccine -Two days after vaccination with five simultaneous injections against nine disease, Hannah Poling was lethargic, irritable, and feverish, and ten days later after vaccination she developed a rash consistent with vaccine induced chickenpox -Diagnosed months later with encephalopathy caused by a genetic mitochondrial enzyme deficiency -It is not unusual for children with such deficits to develop neurologic changes between their first and second years 2. This case is often referred to as conclusive proof (by vaccines = autism advocates) that vaccines lead to autism, even though she had a preexisting genetic condition that was deemed to be worsened as a result of the vaccine she received, and she does not have an autism spectrum disorder

Different Flu Vaccines

1. Inactivated influenza vaccine- Quadrivalent and Trivalent- Y(eggs)- IM, ID 2. Adjuvanted inactivated influenza vaccine- Quad- Y(eggs)- IM 3. Inactivated influenza vaccine, cell based culture- Trivalent- Eggs(Y)- IM 4. Recombinant subunit influenza vaccine- Trivalent- N (eggs)- IM 5. Live attenuated influenza vaccine- Quadrivalent- Y (Eggs)- IN

Preservatives

1. Included in multiple-dose eye solutions for maintaining the product sterility during use a. Cationic wetting agnets: benzalkonium chloride (0.01%) -Used in combination with 0.01%-0.1% disodium edetate (EDTA) -The chelating agent EDTA has the ability to render the resistant strains of P. aeruginosa more sensitive to benzalkonium chloride 3. Mixtures of 0.1% of methyl and propyl hydroxybenzoate (2:1) 4. Alcohol substitutes a. Chlorobutanol (0.5%); effective only at pH 5-6 b. Phenylethanol (0.5%)

Periocular Delivery

1. Includes subconjuctival, Sub-Tenons, and retrobulbar administration a. Advantages: -safer and less invasive than intravitreal administration -offers potential for localized sustained release -can achieve high drug concentrations in vitreous humor for treatment of retinal diseases -reduced systemic side effects b. Disadvantages -ease of administration (injection or surgery) -repeat administration or sustained release systems needed -patient acceptance, particularly repeat injections

What modifications can be made to a drug formulation to increase corneal penetration of topical ophthalmic drugs?

1. Increase drug concentration in formula 2. Increase drug lipophilicity (prodrug) 3. Increase drug contact time with the cornea a. Isotonicity and pH adjustment b. Increase viscosity c. Suspensions (</= 10 microns), ointments, reservoirs d. Punctual occlusion

Ocular Inserts

1. Insoluble Inserts -Multilayer structure consisting of a drug containing core surrounded on each side by a layer of copolymer membranes through which the drug diffuses at a constant rate -Ocusert a. Placed in the inferior cul-de-sac between the sclera and the eyelid and to release pilocarpine continuously at a steady rate for 7 days for treatment of glucoma b. Consists of a drug reservoir (pilocarpine free base and a carrier material, alginic acid), and a rate controller ethylene vinyl acetate (EVA0 copolymer membrane 2. Soluble Inserts a. Comprised of natural (collagen) or synthetic polymers (hydroxypropyl cellulose, methylcellulose, polyvinyl alcohol, ethylene vinyl acetate copolymer) b. Soften with 10-15 sec and gradually dissolves within 1 hour releasing drug

Intravitreal Delivery

1. Involves direct administration of drug into the vitreous cavity by injection or surgical implantation a. Advantages: -high drug concentrations in vitreous humor for treatment of retinal diseases -reduced systemic side effects b. Disadvantages: -difficult administration (injection or surgery) -rapid elimination from vitreous; repeat administration or sustained release systems needed -Patient acceptance, particularly repeat injections -risk of significant ocular side effects (e.g retinal detachment, vitreous hemorraghe, endophthalmitis)

Neovascular (Wet) Age-Related Macular Degeneration (AMD)

1. Leading cause of vision loss in people over 65 years of age 2. overgrowth of blood vessels that rupture Bruch's membrane and causes damage to the macula- area where light is focused that allows us to see

Antigenic Shift

1. Less often than the antigenic drift, the antigenic shift occurs 2. Viruses of different strains swap RNA in a secondary host (an animal that can host both e.g pig (swine flu) or bird (avian flu) -Potential to cause super bug that is so uncommon from other flu strains that protection would be very limited -Also, potential to create a weaker or equally virulent virus -The CDC/WHO can only predict effect once it has affected a large population

Onpratto

1. Lipid Nanoparticle Encapsulating siRNA 2. Positive charge- immunogenicity, salts are small, PEG- large- allergic rxn 3. Required premedication- all pts should receive premedication prior to Onpratto administration to reduce the risk of infusion related reactions -give corticosteroid -Oral paracetamol -intravenous H1 -intravenous H2

The Phosholipid Bilayer: Molecular Scale

1. Lipid bi-layer -Prevents or limits transport of: -Ions and Hydrophilic Molecules 2. Allows passive diffusion of hydrophobic molecules

Onpratto

1. Lipid nanoparticles deliver siRNA 2. Approved in 2018 3. Indication: hereditary ATTR amyloidosis 4. ATTR amyloidosis can lead to the dysfunction of many organs 5. Parenteral drug product: -should be inspected visually for particulate matter and discoloration prior to administration -Route of administration: intravenous infusion 6. Onpratto decreases the production of ATTR through RNA interference 7. Patisiran specifically binds to a genetically conserved sequence in the 3' untranslated region of mutant and wild type transthyretin (TTR) and mRNA

FluMist (Live attenuated Influenza Vaccine)

1. Live attenuated vaccine given intranasally 2. 0.2 mL dose 3. This formulation cannot be given to immunocompromised patients 4. was not recommended for the 2016-2017 and 2017-2018 seasons 5. Recommended since the 2018-2019 season

Toxic Effects of Oligonucleotides

1. Liver and kidney toxicity -clearance mainly through kidney and liver 2. Injection site reaction 3. Immune and interferon like responses -interactions with toll like receptors 4. Off target effects -non-specific binding to other targets

Local Delivery

1. Local means that the drug is primarily delivered to just one region, tissue, or cell type in the body -Can be achieved with targeting or physical location 2. Injection to a specific isolated region or localization via external force 3. Regional delivery examples include: -Lungs (e.g nebulizers, dry powder inhalers) -Mouth (gum, dissolvable strips, patches) -Rectum (suppositories, enemas) -Vagina (foams, suppositories, polymer rings) -Skin (cream, patch)

Why do you think that cyclosporine systemic bioavailability after ophthalmic administration is so low?

1. Low systemic absorption -Large polypeptide drug -many charged groups -unpredictable absorption -P-gp efflux substrate -Erratic absorption across intestinal epithelium 2. Extensive first pass effect if swallowed -Major CYP3A4 substrate Other notes: -topical- dry eye -oral- solid organ transplant -cyclosporine- big ugly peptide, bad bioavailability, small amount in blood stream, toxic medication- solid organ transplant

Luxturna- Sparks Therapeutics

1. Luxturna is a one time gene therapy for individuals with an inherited retinal disease -Disease is caused by mutations in both copies of the RPE65 gene -Individuals must have enough remaining viable cells in the retina 2. Luxturna is an *adeno-associated virus vector based gene therapy 3. Viruses carrying healthy genes are injected into the retina of the patients 4. Procedure slows down vision loss but does not reverse it

Luxturna- Sparks Therapeutics

1. Luxturna is a onte time gene therapy for individuals with an inherited retinal disease -Disease is caused by mutation in both copies of the RPE65 gene -Individuals must have enough remaining viable cells in the retina Expensive; $425,000 Luxturna uses the adeno-associated viral vector subtype 2 (AAV2) to carry a functional copy of the RPE65 gene into the retinal pigment epithelial (RPE) cells to compensate for the RPE65 mutation -Viruses carrying healthy genes are injected into the retina of the patients -Procedure slows down vision loss but does not reverse it

Examples of Advanced Dosage Forms

1. Lymphoseek- a. locally injected close to tumor SUBQ space other. After injection, lymphoseek drains to the tumor and preferentially drain into lymph node b. FDA approved 2. EndoTag-1 a. positively charged bind to the negative charged things b. binds to negatively charged tumors c. FDA approved 3. Zevalin and Bexxar a. Target CD20 on Bcells for lymphoma b. Zevalin ytrrium-90 ibritumomab tiuxetan c. BEXXAR- iodine 131 tositumomab d. FDA approved 4. Encode Phloral a. pH and enzymatic release mechanism b. Enzymatic release is dependent on enzymes released by local microbial flora in the colon (red dot area) c. Microparticle -Mostly outer layer -Ph coating -inner coating- colon flora eats allowing drug release

Types of Vaccines

1. On end reduced efficacy because the immune system needs a danger signal to activate it, which something like a protein does not normally have 2. Safety concerns because vaccine components could become virulent

Squalene based adjuvants only used in influenza vaccines

1. MF59 (Novartis)- Fluad (seasonal), Focteria (pandemic), Aflunov (pandemic) 2. AS03- Pandremix (pandemic), Prepandrix (pandemic) 3. AS03 and increased anaphylaxis- a. During 2009 H1N1 pandemic, it was used and surveillance of its use in Quebec, Canad notices a significant increase in anaphylaxis Typical trivalent vaccine: <1/ million anaphylaxis incidences For AS03-adjuvanted monovalent pandemic A1/H1N1 vaccine: 8-13 million anaphylaxis incidences 4. One study noticed no differences between lots except for one lot which had an incidence of 19/million 5. AS03-adjuvanted monovalent pandemic A/H1N1 vaccine: 8-13 million/ anaphylaxis incidences 6. One study noticed no differences between lots except for one lot which had an incidence of 19/million 7. AS03 and narcolepsy a. Pandemrix, a monovalent 2009 H1N1 influenza vaccine that contains AS03 (Pandemic vaccine) b. In Finland and Sweden, Narcolepsy rates in 5-19 olds increased in population where people were vaccinated (1.67/100,000 people) versus non vaccinated populations (0.95/100,000 people) c. Narcolepsy was also linked to the vaccine in the UK d. Studies have been unable to determine the cause

Example of First Order Active Targeting

1. Magnetic nanoparticles with drug are injected into the synovial fluid around the knee 2. Magnets are used to localize the particle 3. First order- -Systems that deliver the drug to the capillary bed o the tissue

Tear Formation and Drainage

1. Meibomian glands along eyelid produce meibum (oil) in tears to reduce tear evaporation 2. Epiphora: abnormal overflow of tear fluid down the cheek, caused by nasolacrimal duct obstruction

Gene Approaches to the Therapy of Diseases

1. Mode of therapies: a. DNA or mRNA mediated gene therapy: Introduction of a gene of interest Replacement: Gene product/ protein missing Augmentation: Gene product inactive-mutation Correction: Gene product less active- mutation 2. Gene editing- CRISPR (Clustered Regularly Interspaced Palindromic Repeats) a. Correct mutated genes b. Introduce new genes or remove existing genes 3. Antisense therapy or RNA interference therapy: sequence is complementary to mRNA of interest -siRNA (short interfering RNA) -antisense DNA Deletion/Knockdown: Gene product responsible for disease state

Genetic Approaches to Therapy of Diseases

1. Modes of therapies a. DNA or mRNA mediated gene therapy: Introduction of a gene of interest -Replacement: Gene product/ protein missing -Augmentation: Gene product inactive- mutation -Correction: Gene product less active- mutation b. Gene editing- CRISPR (Clustered regularly interspaced short palindromic repeats) -correct mutated genes -introduce new genes or remove existing genes c. Antisense therapy or RNA interference therapy: sequence is complementary to mRNA of interest -Deletion/Knockdown of gene product responsible for disease state -siRNA (short interfering RNA) -antisense DNA

Case 1- Mipomersen

1. Modification in Mipomersen: Phosphorothioate (PS) backbone 2'-O methyoxyethyl (2'-MOE) 2. Kynamro is an antisense oligonucleotide inhibitor of apoliprotein B-100 synthesis 3. Used to treat familial hypercholesterolemia -A disorder that is passed down through families -It causes LDL (bad) cholesterol to be very high Annual Cost: $176,000 once weekly injection

Influenza growth

1. Most influenza vaccines are grown in chicken eggs. There is no longer concern for egg allergic individuals 2. In 2015, the FDA changed their position regarding egg allergies and the influenza vaccines -Previously a. Egg allergic patients were required to wait 30 minutes after the shot b. Flublok or Flucelvax was recommended 3. Currently a. Egg allergic patients can receive any influenza vaccine b. They do not have to wait 30 minutes

Drugs used int he eye:

1. Motics: pilocarpine, HCl 2. Mydriatics: atropine 3. Cycloplegics: atropine 4. Anti-inflammatories- corticosteroids 5. Anti-infectives (antibiotics, antivirals, and antibacterials) 6. Anti-glaucoma drugs (e.g pilocarpine HCL) 7. Surgical adjuncts (e.g irritating solutions) 8. Diagnostic drugs (e.g sodium fluorescein) 9. Anesthetics (tetracaine)

Immunogenecity of Nucleic Acid Therapies

1. Nucleic Acid Therapies are multicomponent drugs. Each part of the drug can induce an immune response 1. Delivery vehicle/vector a. Non-viral vector -Cationic/ionizable lipids can react with toll-like receptors and induce an immune response 2. Viral vectors like the adeno-associated virus (AAV) have immunogenicity issues: a. Many patients have neutralizing antibodies against AAV that can impair with the AAV's transduction efficacy. 3. Nucleic acids -siRNA or antisense oligos can be recognized by the immune system -Toll like receptor 3 (TL3) recognizes double stranded RNA and TL7 and TL8 recognize single-stranded RNA -Sequence optimization and chemical modifications can partially address the immunogenicity issues.

Immunogenicity of Nucleic Acid Therapies

1. Nucleic acid therapies are multicomponent drugs. Each part of the drug can induce an immune response: a. Delivery vehicle/vector i. Non viral vector -Cationic/ionizable lipids can react with toll like receptors and induce an immune response ii. Viral vectors like the adeno-associated virus (AAV) a. Virus (AAV) have immunogenicity issues: many patients have neutralizing antibodies against AAV that can impair with the AVV's transduction efficacy. b. Encoded protein can cause immunogenecity c. Nucleic Acids -siRNA or antisense oligos can be recognized by the innate immune system -Toll like receptors 3 (TL3) recognizes double-stranded RNA and TL7 and TL8 recognize single stranded RNA -Sequence optimization and chemical modifications can partially address the immunogenicity issues

Challenges associated with Nucleic Acid Delivery

1. Nucleic acids are highly negatively charged -leads to low uptake into cells 2. High molecular weight -plasma DNA: 1 to 1000 kbp -mRNA: 1500 to 2000 nucleotides (single stranded) -siRNA: 21 bp -miRNA: 21 bp -Macromolecules are taken up by cells much more inefficiently than small molecules 3. Enzymatic degradation of nucleic acids -Blood nucleases -Interstitial nucleases -Cellular nucleases

Why vaccines over infection?

1. Often a vaccine is better than an infection -Example: the clinical manifestation of tetanus are due to a tetanus exotoxin -The toxin is so potent that small amounts of the toxin can make you sick, but not stimulate as great of an immune response as the vaccine -Preexisting antibodies developed by the vaccine are effective in preventing sickness -Similarly with diptheria 2. Higher risk for complications and mortality with infection -Chicken pox as an adult -Mild case of Pertussis, whooping cough, in an adult can be lethal in an infant 3. Infection from diseases like Measles, Mumps, Rubella, and Chicken Pox can provide life-long immunity; however, they can also cause significant complications (e.g sterility, deafness, meningitis, other organ inflammation) and death

Endo-Tag

1. Paclitaxel slightly positively charged lipids 2.Interacts with newly formed, negatively charged endothelial cells 3. Chemotherapeutic stops the growth of newly forming blood vessels that are needed to feed the tumor

Subunit Vaccines use parts of the pathogen and an adjuvant

1. Part of the pathogen 2. Part of the pathogen with adjuvant Examples: Hepatitis B Influenza Haemophilus influenza type b (Hib) Pertussis Pneumococcal Meningococcal Human papillomavirus 3. Subunit vaccines usually have two parts 4. Adjuvants are used to irritate the immune system response through danger signals. Danger signals are activated by recognizing flagella, sugars, or nucleic materials commonly on/in pathogens. 5. Antigens (e.g proteins, VLPs) are then used to target the irritation and initiate an immune response.

Inactivated or killed virus

1. Pathogens are killed and cannot replicate, but capsid and other proteins are enough to generate a protective immune response 2. Protective immunity from the killed organism with immunogenicity as effective as live organism Examples: -Influenza vaccine -Polio -Hepatitis A

Restasis Warnings and Precautions

1. Patient should never touch the ophthalmic dosage form container to the eye. This could result in contamination. 2. Patient should not use topical ophthalmic drugs while wearing contacts. After administering the drug, wait to install contact until drug has been absorbed or washed away from the eye. Patients should also wait between administering different product. Read about ophthalmic administration in compounding book. a. Reason for this is that it could lead to leaching or bigger issue adsorption - less absorption because drug gets stuck to the contact lens

General Barriers to Drug Absorption:

1. Physical For example: cells, cell membranes, fluids between cells 2. Biochemical -Enzymatic degradation

Topical Delivery: Factors Affecting Corneal Penetration

1. Physiological factors -Tear production/drainage (normal volume of tear = 7 microliters, the blinking eye can accommodate a volume of up to 30 microliters without spillage) 2. Drug factors -Concentration instilled into eye (stability?) -Solubility -pKA -Partition Coefficient (Fick's Law) -Molecular Weight

Enhanced Permeability and Retention effect (EPR) with IV injection

1. Present in solid cancer, inflammation, and site of vessel damage 2. Cancer cell must grow their own vasculature when they grow around 1 cm or larger 3. This vasculature tend to be leaky -Poorly aligned defective endothelial cells with wide fenestrations 4. Working against the EPR effect is a negative pressure that pushes macromolecules out of the cancer and into the vasculature a. No lymphatics in cancer = buildup of waste and other fluids

Topical Delivery

1. Primary route of administration for treating ocular diseases 2. Ideal formulation: -good corneal protection -Prolong contact time with corneal tissue -Simplicity of instillation for the patient -Non irritating and comfortable form -Appropriate rheological properties 3. Advantages: -High drug concentrations in anterior chamber -Reduced systemic side effects -Ease of administration (vs parenteral or intraocular) 4. Disadvantages: -Limited delivery of drug to back of eye -Requires drug in solution or suspension -More difficult to administer than tablets/capsules

Benzalkonium Chloride (BAK)

1. Pros a. Excellent antimicrobial activity and chemical stability b. active against Pseudomonas aeruginosa especially when combined with EDTA 2. Cons a. accumulates in ocular tissue b. conjunctival irritation c. dose-dependent corneal cytotoxicity d. incompatible with salicylates, nitrates, and anionic compounds (can precipitate out with large bags?)

VLP- virus like particles

1. Protein elements from viruses self assemble into a particle 2. Examples: -Hepatitis B a. GlaxoSmithKline Engerix b. Merck and Co, Inc's Recombivax HB -Human papillomavirus -Cervarix -Gardasil Formulations contain alum

What is the main cause of blindness from contaminated ophthalmics? What is a formulation solution used to help reduce the risk of contamination by this agent?

1. Pseudomonas aeruginosa 2. EDTA, a chelating agent, has the ability to render strains of P. aeruginosa more sensitive to benzalkonium chloride, a cationic wetting agent. So often these two are used in combination in multiple dose eye solutions.

What is the difference between antisense therapy and RNA interference therapy?

1. RNA interference (RNAi) utilizes the multi-protein RNAi induced silencing complex (RISC) containing a siRNA to specifically degrade the targeted RNA (single strand RNA) 2. Antisense oligonucleotides, DNA, bind to targeted RNA and use endogenous RNAse H1, an enzyme that cleaves the RNA in an RNA/DNA heteroduplex (double strand RNA) 3. Oligonucleotide therapies -Patients are pre treated with corticosteroids to reduce inflammation associated with oligonucleotide therapies

Flubok

1. Recombinant influenza vaccine- free of egg proteins 2. HA protein grown by Baculovirus in caterpillars 3. FDA approved in 2012 4. 0.5 mL dose (IM)

Refrigerator Storage vs Freezer Storage

1. Refrigerator Storage a. 36 to 46 degrees Farenheit b. Vaccine: Hep A and Hep B, Hib, HPV, Influenza, IPV, Meningococcal, Pneumococcal, Rotavirus, DPT, Zoster (subunit), MMR c. Water bottles on top and bottom labeled "Do not drinK" d. Store in original packaging with lids closed e. Store diluent with corresponding vaccine 2. Freezer Storage -58 to +5 degrees Farenheit -Vaccines: Zoster (live), MMR, and Measles, Mumps, Rubella, and Varicella -Never store diluent in the freezer -Keep water bottles in the back, against the walls, and in doors Pfizer Covid 19 vaccines require -112 degrees Farenheit storage Moderna requires freezer storage Store in original packaging with lids closed Store in center 2-3 inches always from the walls, ceiling, and doors Do not pack tightly

Formulation Issues

1. Retention time at absorption site (superficial absorption of drug into conjunctiva and sclera and rapid removal by the peripheral blood flow) -Viscosity (polyvinyl alcohol, carbomers) 2. pH -Buffers (low buffer capacity to allow return to normal pH upon blinking) -A wide range of pH values are used to enhance shelf-life 3. Tonicity -Lactrimal fluid is isotonic with blood (0.9%) -The eye can tolerate 0.6-2.0% NaCl -Some formulations are hypertonic to enhance absorption 4. Solubility enhancement -Co-solvents -Surfactants (non-ionic, polysorbates (Tweens)) 5. Stabilizers -Anti oxidants 6. Ingredients to impart color, odor, or flavor are prohibited

contains the sugar deoxyribose

DNA

GSK adjuvant

1. Shingrix is safer and is more effective than Zostavax because it is an adjuvanted subunit vaccine (protein based), not a live attenuated viral vaccine 2. QS-21 and monophosphoryl lipid A are combined 3. QS-21 in a liposome 4. It is in the FDA approved shingles vaccine (Shingrix) and FDA-IND approved for malaria vaccine 5. QS-21 can not be made synthetically and is a natural product from the bark of the Chilean soapbark tree 6. TLR4 agonist 6. QS-21 aalone (without MPL) is not very immunostimulatory

Chicken Pox as a Child does not Translate to Shingles Protection as an Adult

1. Shingrix is safer, has fewer side effects and is more effective than Zostavax. Evein if they received Zostavax, they should receive Shingrix. 2. Zostavax- is a live attenuated vaccine 3. Shingrix- Subunit vaccine contains adjuvant- MPL and liposomal QS21 (ASO1) 4. Patients should wait 8 months between vaccines 5. Protects against Shingles which can lead to a painful rash by the same virus as Chicken pox (varicella zoster) 6. 1 in 3 contract Shingles, mostly individuals > 60 years of age, Dormant chicken pox can lead to shingles

Take home points

1. Shingrix is the preffered shingles vaccine and is an adjuvanted subunit vaccine that has fewer side effects than live attenuated viral vaccine Zostavax (which is now discontinued). Patients who have received Zostavax should also receive Shingrix 2. Influenza vaccine are most commonly inactivated viral vaccines grown in egg, but there are also subunit protein and live-virus vaccines -If egg allergies are a concern, despite FDA research supporting they are safe, caterpillar grown subunit vaccine Flublok or mammalian cell grown inactivated viral vaccine Flucelvax are egg free -Latex allergy patients should Fluad due to the syringe -Elderly patients are recommended to receive inactivated high-dose Fluzone or adjuvanted Fluad 3. Rates of anaphylaxis, likely PEG, have been observed with Covid-19 LNP vaccine formulations. Events are rare, but it is recommended if patients have a history of anaphylatic reactions that they not receive the vaccine 4. Vaccines require cold chain storage wherein they are constantly in climate controlled conditions. Also, they need to be stored properly in both the fridge and freezer

Examples of how the same delivery system can do both

1. Some factors that dictate local vs systemic delivery: a. Drug properties b. Delivery system properties c. Physiological (e.g microenvironment, local disease etiologies conditions) 2. Example: DepoFoam a. can release drug into the bloodstream via the interstitial space (systemic) -SubQ -IM b. can release drug into a body compartment, such as a joint (local) -Intrathecal -Intra-articular -Intraperitoneal -Subcutaneous -Epidural -Intraocular

Intravitreal Medications

1. Some indications a. Age-related macular degeneration b. Macular edema c. Infections of the vitreous compartment 2. Some drugs a. Lucentis (ranibizumab) b. dexamethasone c. ganciclovir d. vancomycin e. amphotericin B -Procedure is usually down in opthomologist office

Explain why sterile membrane filtration and autoclaving might not be suitable for certain opthalmic products

1. Sterile membrane filtration: not suitable for suspensions 2. Autoclaving: not suitable for heat labile drugs and plastic containers

Flucelvax

1. Subunit vaccine grown in mammalian cells 2. FDA approved in 2016 3. 0.5 mL dose (IM) 4. Some virus is less effective when grown in eggs because the glycosylation of protein on the virus affects immune responses. Growth in a mammalian cell can offer protein glycosylation closer to humans.

Systemic vs Local Delivery

1. Systemic means the drug is delivered throughout the body, more or less equally 2. Local means that the drug is primarily delivered to just one region, tissue, or cell type in the body 3. Some factors that dictate local vs systemic delivery a. Drug properties b. Delivery system properties c. Physiological (e.g microenvironment, local disease etiologies condition 4. Each organ has unique challenges and features that distinctly interact with different therapeutics and formulations -Some organs/ barriers are more challenging to overcome for specific drugs or formulations 5. At the smaller scale, each cell has unique challenges and features (e.g specific cellular pathways) 6. Even smaller, there exists unique challenges and features at the molecular scale

Advanced Drug Delivery Dosage Forms

1. Targeting EPR effect (Utilizing local microenvironment features) -Targets nanoparticles to sites like solid cancers, temporarily 2. Asymmetric Delivery (Formulation/ delivery strategies) -Concentrates drug release at tissue surface 3. Controlled Release (formulation/delivery strategies) -Sustained release of drug over time -Stimuli-responsive release Graphic shows a dosage form with targeting, controlled release and asymmetric delivery

RPE65 protein production by AAV2

1. The adenoassociated viral vector serotype 2 (AAV2) is taken up into retinal pigment epithelial cells 2. In the cell the AAV2 is released from the endosomes 3. The AAV2 is trafficked to the nucleus and releases its single stranded DNA (therapeutic gene) in the nuclues 4. The single stranded DNA is converted to dsDNA 5. The dsDNA is transcribed to mRNA and the RPE65 protein is expressed

Building Block of Nucleic Acid

1. The building block of nucleic acids are called nucleotides -Nucleotides are composed of a a. a nitrogenous base b. a five membered carbon ring (sugar) c. a phosphate group DNA bases: Adenine (A) Guanine (G) Cytosine (C) Thymine (T) RNA bases: Thymine is replaced by Uracil (U)

Take Home Points

1. The building blocks of nucleic acids are called nucleotides. Nucleotides are composed. of a nitrogenous base, a five membered carbon ring (sugar), and a phosphate group 2. Antisense oligonucleotides are small DNA strands that bind to a complementary messenger RNA (mRNA). This blocks the cell's ability to use the mRNA to make a protein. 3. Nucleic acids have a high molecular weight and are negatively charged. Thus, they need to be attached to a targeting ligand or encapsulated into a viral or non-viral vector to be delivered into cells. 4. Nucleic acid therapy can cause immunogenecity through a. the delivery vehicles themselves, the protein that is encoded by the gene and the nucleic acid cargo

Vaccines that require cold chain storage

1. The cold chain means that there is a temperature controlled environment from vaccine processing to use -Manfacturer -Transportation to distributor -Delivery to and storage at provider -Administration to patient 2. Cold Chain Breakdown -Heat, light, and cold can break the cold chain -Freezing can destroy some refrigerated vaccines -Each incident can result in loss of potency -Vaccine appearance is not a reliable indicator

DNA is more chemically stable than RNA

DNA 1. deoxyribonucleic acid 2. ribonucleic acid

Restasis

1. The extent of systemic exposure after topical administration depends on the physicochemical properties and pharmacokinetics of the drug 2. Restasis in 12 months had blood cylosporine systemic levels below 0.1 ng/mL quantitation limit. There was also no detectable drug accumulation in blood during 12 months of treatment with Restasis ophthalmic emulsion. 3. Not super potent because no detectable side effect- drain into lacrimal duct so little big ugly molecule and bad absorption- low systemic blood concentrations

Lymphatic System

1. The lymph system is the overflow system of the body 2. The pressure generated by your heart leads to fluid coming out through the capillaries -This fluid flows through the extracellular tissue space picking up molecules along way -The fluid is then recycled back into the blood stream in the venous system 3. The lymphatics (and blood) also carry immune cells throughout the body, particularly to the lymph nodes 4. Drugs that leave the capillaries can also be taken up by the lymphatics, which further complicates their delivery and can delay it to where it needs to go

Summary

1. The primary posterior barrier to ophthalmic delivery is the blood retinal barrier 2. The primary anterior barrier to ophthalmic delivery os the cornea 3. Systemic or local administration can be used to deliver drugs to the eye. -anterior eye (local administration)- macula- don't treat with eye drops for posterior eye- eye drops are for topical administration (not systemic delivery only local delivery) 4. The most common preservative in ophthalmic formulation is benzalkonium chloride, but it has limitations (can accumulate which causes irritation and is a cationic wetting agent that acts as a surfactant.. can disrupt membranes) 5. Opthalmic administration may result in systemic drug exposure via drainage into the nasolacrimal duct

Movement of drug through a cell membrane

1. There are two ways that the molecules move through the membrane: a. The passive transport (diffusion) b. Active transport (cell transporter) 2. The only means of passive transport is diffusion

Take Home points

1. There are various routes for ocular delivery, but topical delivery is the most common 2. Physiological, drug molecule and formulation factors all affect corneal penetration 3. All ophthalmic products must mass a USP sterility test -Several methods for sterilizing ophthalmic products -Compounding pharmacies? 4. Alternate modes of delivery -intravitreal -Inserts -Iontophoresis -Gene therapy

Why people question vaccines: Thiomersal

1. Thiomersal (mercury based preservative) -Mercury is a neurotoxin as a free metal -Mercury posoning does not result in autism like symptoms (Mad Hatter) 2. There is no convincing scientific proof to support this claim. WHO, FDA, NIH, and CDC all agree 3. Thiomersal concentrations have steadily decreased since 1999 in vaccines while autism rates have increased 4. Concern that mercury (thiomersal) might have synergistic effects with other metals and toxicants 5. FDA has been actively eliminating thiomersal from vaccines -Many vaccines are now preservative (e.g Thiomersal) free -Since 2003 all preservative loaded vaccines for Hib, HepB, and DTP have been used up

How can topical delivery of ophthalmic drugs causes systemic side effects?

1. Through draining through the puncta into the canaliculi into the nasal septum, where they can be absorbed into the systemic system.

Systemic Delivery Barriers/Challenges: Clearance in Liver/Spleen

1. Tissue resident macrophages or other organ specific cell types a. Macrophage job is to sequester and eliminate foreign pathogens i. Many formulations (e.g nanoparticles) are quickly recognized and cleared from circulation - Macrophages have dominant presence in liver/spleen and this contributes to drug-induced liver toxicity

Drug Delivery to the Eye

1. Topical ocular (eye drops) 2. Systemic (IV, oral, IM, SQ) 3. Intravitreal 4. Periocular (transcleral) 5. Subretinal

Active Strains change

1. Typically only 1 B strain is included, 2020-2021 strain has two 2. Influenza A infects animals (birds, pigs) and humans 3. Influenza B only infects humans 4. Influenza C infects pigs and humans and only cause mild illness 5. Strains are set by the CDC after global surveillance information is provided by the WHO

General Structure of mRNA

1. UTR: translational efficiency is regulated by their length, structures, and regulatory elements 2. 5' CAP: The efficiency of capping and the cap structure impact innate sensing and protein production 3. 3' Poly A tail: properties such as length, are important for translation and protection of the mRNA molecule 4. CDS (coding sequence) -Modification of sequence, such as codon optimization, have contributed to improved expression 5. Purity: Removal of impurities reduces innate sensing promoting expression 6. No method for solid phase synthesis; enzyme link nucleotides- beneficial and helps translocation in cell

Jennerian vaccine

1. Vaccination with cowpox provides protection against both smallpox and cowpox 2. Edward Jenner noticed that milk maids did not have smallpox scars and though they were exposed to a pathogen that protected them

Why People question vaccines: Vaccine Overload

1. Vaccine overload a. Some parents seek alternative schedules for vaccine believing that administration of several vaccine at once can overload the immune system and result in conditions like autism b. The immune systems can respond to thousands of invaders at a single time c. The pathogen load given by vaccines constitutes only a fraction of the antigens typically encountered d. The antigen load in vaccines has decreased dramatically to be less than 10% of the load given in 1980's -In contrast, autism rates have increased since 1980, disproving a link -Twice as many diseases protected against. 97% less load on the immune system

Systemic Delivery Barriers/Challenges: Vascular Circulation

1. Vascular barriers/challenges a. Blood constituents -Serum proteins -Blood cells b. Blood flow -Access to diseased organs/tissues/cells

Visudyne (verteporfin)

1. Verteporfin is activated by application of a nonthermal laser after infusion 2. Activated drug provides energy to produce reactive oxygen species 3. Damages epithelium and occludes choroidal neovasculature 4. Temporary photosensitivity

Both share adenine, guanine, and cytosine

DNA and RNA

From less concentration to greater concentration

During a change in osmosis, solvent moves:

CRISPR

Gene editing can be performed with _________

What gene carriers (vectors) do we use to deliver nucleic acids?

1. Viral Vectors a. Retrovirus Some potential advantages- a. Integrate genes into host chromosomes b. Offers chance for long-term stability Some Drawbacks- a. Genes integrate randomly, so might disrupt host genes b. Many infect only dividing cells 2. Adenovirus Some potential advantages- a. Large capacity b. Most do not cause serious disease Some potential drawbacks- a. Genes may function only transiently due to the lack of integration or attack by immune system 3. Adeno-associated virus Some potential advantages- a. Integrate genes into host chromosomes b. Cause no known human disease Some drawbacks- a. Small capacity foreign genes 4. Non-viral Vectors Some potential advantages - Have no viral genes, so do not cause disease Some Drawbacks -Often times less efficient than viruses at transferring genes/nucleic acid to cells 5. "naked" Nucleic Acid Some potential advantages- a. Have no viral genes, so do not cause diseases Some Drawbacks- a. Inefficient at nucleic acid/ gene transfer b. Unstable in the body (needs chemical modifications)

Approaches to Oligonucleotide Delivery

1. Viral Vectors 2. Non viral vector -Nanocarriers (lipid nanoparticle, poylmers, etc) 3. Oligonucleotide conjugates -Oligos are chemically modified for enhanced

Gene Carriers (vectors) used to deliver nucleic acids

1. Viral vectors A. adeno-associated Advantages a. Interact genes into host chromosomes b. Cause no known human diseases Some drawback a. Small capacity foreign genes B. Retrovirus Advantages- a. Integrate genes into host chromosomes b. Offers chance for long-term stability Some drawbacks a. Genes integrate randomly, so might disrupt host genes b. Many infect only dividing cells C. Adenovirus Advantages- a. Large capacity for foreign genes b. Most do not cause serious disease Some drawbacks- a. Genes may function only transiently due to lack of integration or attack by immune system 2. Non-viral vectors A. Liposomes Advantages- Have no viral genes, so do not cause disease Disadvantages- Oftentimes less efficient than viruses at transferring genetic/nucleic acids to cells B. Naked Nucleic Acids Advantages- Have no viral genes so do not cause disease Some drawbacks- Inefficient at nucleic acid/gene transfer Unstable in the body (needs chemical modifications)

Topical Delivery Systems

1. Viscous solutions/suspensions (e.g Trusopt) -increases residence in eye which increases bioavailability -maximum 3X increase in bioavailability -can cause transient blurring of vision 2. Ointments (e.g antibiotic ointments) -increases residence in the eye which increases bioavailability and can provide sustained release -Can cause blurring of vision; often used only at night 3. Gels (Pilopine) -Increases residence in eye which increases bioavailability and can provide sustained release -can cause blurring of vision; often used at night

Genetic information flows from DNA to RNA to Protein

1. When a cell divides, each of its DNA double strand splits into two single strands. Each of these single strands act as a template for a new strand of complementary DNA. This process is known as DNA replication 2. Transcription is the process by which DNA is copied (transcribed) to mRNA. The mRNA carries the information needed for protein synthesis. The process relies on Watson-Crick base pairing, and the resulting single strand of RNA is the reverse complement of the original DNA sequence 3. The RNA is then translated into proteins. Each group of three bases in mRNA constitutes a codon, and each codon specifies a particular amino acid that makes up the protein

Virus genes are removed from the vectors and replaced with a therapeutic gene

1. Wild type adeno-associated virus (4800 bp in size) 2. Recombinant AAV vectors- therapeutic gene (up to 4800 bp)

US Vaccine Injury Compensation Program (VICP)

1. aka Vaccine Court 2. Funded by a tax on vaccines 3. Established in 1980s after diphtheria, pertussis (whooping cough), and tetanus (DPT) vaccine scare -Even though claims of side effects were later generally discredited, large jury awards had been given to some claimants of DPT vaccine injuries 4. Court only requires a. a medical theory causally connecting the vaccination and the injury b. a logical sequence of cause and effect showing the vaccination was the reason for the injury c. showing of a proximate temporal relationship between vaccination and injury

Chemical Modifications to Improve Stability and Decrease Immunogenecity of Nucleic Acids

1. backbone and ring modifications 2. Sugar modifications

Delivery to the Posterior Eye

1. biggest barrier of drug delivery to posterior eye: blood-retinal barrier (tight junctions in retinal pigment epithelial cells) 2. Retinal capillary endothelial cells and retinal pigment epithelium cells (RPE) also contain tight junctions 3. RPE permits selective transport and is being investigated as a mechanism for targeted delivery 4. Systemic (PO, IV) 5. Routes- Intravitreal, Periocular, Subretinal

Givlaari and Patisiran

1. chemical modifications: PS (phosphorothioate backbone) 2. 2-F 3. 2-O Me modified siRNA

Systemic Delivery Barriers/Challenges: Capillary Filtration

1. different sized blood vessels (arteries, veins, capillaries) can trap to prevent transport of therapeutics 2. Large delivery systems get trapped and can alter local delivery 3. Major capillaries- RBC can increase oxygen to facilitate oxygen delivery

Targeted Drug Delivery

1. drug carrier (aka dosage form) systems that place a drug at or near the receptor site -Can include local delivery methods 2. Groups a. Passive Targeting -Exploitation of a natural (passive) disposition to deliver the drug b. Active Targeting -Alternations of the natural disposition of a drug carrier to deliver the drug 3. Classifications a. First order targeting -Systems that deliver the drug to the capillary bed o the tissue b. Second order targeting -Specific delivery of a drug to a special cell type, such as tumor cell, and not to normal cells (antibody is an example) c. Third order targeting -Delivery specifically to the internal or intracellular site of a cell (specific cellular component) 4. Outer barriers to inner barriers: Inner barriers require passage through outer barriers

Luxturna- What is the function of each component?

1. genome is adeno associated vector 2. everything else adjusts pH and tonicity of the solution

subunit

The safest type of vaccine are ______ vaccines, but a major drawback is that they will not activate a strong immune response by themselves

live-attenuated

The type of vaccine often with the strongest immune response is a _______ vaccine but it can have safety risks, especially immunocompromised individuals

Restasis (cyclosporine ophthalmic emulsion)

1. invert the unit does vial a few times to obtain a uniform, white, opaque emulsion before using 2. Instil one drop of Restasis ophthalmic emulsion twice a day in each eye approximately 12 hours apart 3. Restasis can be used concomitantly with artificial tears, allowing a 15 minute interval between products. Discard vial immediately after use. Additional Notes: coat in oily- tear on top oil and water do not mix -> barrier -> aqueous bead out and fall out -> intended for single use- discard vial after single use- single use no preservative- throw away immediately- expire- could introduce contaminant- *microbiological stability compromised a. *Exam Q: single use vial has no preservative and if you reuse a single use vial, microbiological stability is compromised

Fluzone

1. many dosing options, some better for elderly patients 2. Fluzone trivalent a. IM (high dose)- better for elderly volume- 0.5 Total HA- 180 microgram Formaldehyde- </= 100 microgram Octylphenol Ethoxylate- </= 250 micrograms b. IM a. IM (high dose) volume- 0.5 Total HA- 30 microgram Formaldehyde- </= 50 microgram Octylphenol Ethoxylate- </= 125 micrograms c. ID volume- 0.1 Total HA- 27 microgram Formaldehyde- </= 20 microgram Octylphenol Ethoxylate- </= 50 micrograms d. High dose Fluzone is recommended for the elderly (age greater than 65) because high amount of antigen helps generate an immune response for their waning immunity

Recap of EPR

1. only occurs for a discrete period of time in solid tissue cancer 2. At first there is enough room in the cancer tissue that the contents of the blood can enter. Basically the pressure of the blood is greater than the pressure inside the cancer. 3. Net flow of material into the cancer 4. As time goes on- things build up over time in the tissue: a. Cell waste since there are no lymphatics b. Whatever is coming in from the blood 5. Over time, the room fills up and becomes over filled. This creates a pressure pushing the contents of the cancer tissue back out into the blood. At this point, EPR is no longer present. -Net flow of material is into the blood from the cancer.

Chemical Modifications to Improve Stability and Decrease Immunogenicity of Nucleic Acids

1. position2 needs to be chemically modified to stabilize/immunogenicity issues

Composition of GIVLAARI

1. siRNA is chemically modified to enhance stability 2. Targeting ligand (GalNac) allows targeted delivery to hepatocytes in the liver

Gene silencing

1. siRNA= short interfering RNA 2. Double stranded RNA strand, 202-5 base pairs in length 3. Once inside the cell, the siRNA is loaded into the mult-subunit RNA induced silencing complex (RISC) 4. Here, the sense strand dissociates from the anti-sense strand 5. The antisense RNA strand guides RISC to the complementary site in the target mRNA. 6. The siRNA-loaded RSIC has catalytic activity and is recycled for several rounds of RNA cleavage

MF59

1. squalene based adjuvant 2. Two squalene (shark liver oil) and water emulsion based adjuvants are approved -MF59 (squalene, polysorbate 80, span 85) -D,L- alpha-tocopherol (Vitamin E), squalene, polysorbate 80 3. These adjuvants work through a depot effect where vaccine components are released over time to stimulate a strong immune response

Moderna and Pfizer mRNA vaccine

1. synthetic mRNA is packaged in a lipid nanoparticle that delivers the instruction to the cell 2. Once inside the cell, its cellular machinery follows mRNA instructions to produce the viral proteins. This is displayed on the surface of the cell and stimulates an immune system response

Delivery to the anterior eye

1. the biggest barrier to the anterior eye: cornea/ blood aqueous barrier -Endothelium of iris/ciliary blood vessels and ciliary epithelium -Intracellular permeation restricted by tight junction complexes Anterior topical delivery- cornea **

Take Home Points

1• There are two main approaches to target RNA: double stranded RNA-mediated interference (RNAi) and antisense oligonucleotides (ASO). Both approaches are used clinically to silence genes/proteins. 2. Oligonucleotides are mainly cleared by the liver and kidney => can cause toxic effects to the liver and kidney. 3. To enhance the stability and reduce immunogenicity of nucleic acids, they can be chemically modified at the backbone, the ring, and the phosphate group. 4. Chemically modified nucleotides are used when nucleic acids are delivered in their naked form and when they are delivered in lipid nanoparticles. 5. Nucleic acid therapy can cause immunogenicity through: (a) the delivery vehicles themselves, (b) the protein that is encoded by the gene, and (c) the nucleic acid cargo.

Fluzone high dose or Fluad (not Flumist... Not fluzone ID, not Flucelvax or Flubok)

A 65+ elderly patient wants to get an influenza vaccine. Which is their best option?

proteins

A VLP is comprised of assembled viral _____ that form a nanoparticle

DNA

A new gene can be introduced with (DNA/siRNA) therapy

mRNA/DNA based gene therapy/CRISPR

A new gene can be introduced with _________

A solvent

A solute is what is dissolved in:

dissolved in

A solute is what is dissolved-in/comprises the solution

3L

About how much lymph is produced in a human approximately per a day?

adjuvant

Alum is a common ______ that is used in many subunit vaccine. With other similar agents including those in the GSK adjuvant system, CpG and MF59.

more

An osmotically driven gradient back into the vessels is created because (more/fewer) proteins are in the blood than the extracellular space where the lymph is.

10%; double

Antigen load is a concern of a few individuals because they incorrectly think that too many antigens will overwhelm the immune system. The number of antigens in vaccines is less than (50%/10%) of what it was in 1983, with double/quadruple the number of diseases covered.

Mediate gene silencing

Antisense and RNA interference therapeutics

silencing/downregulation

Antisense therapy or RNA interference therapy mediate the ____________ of genes

one half to one third

Compared to blood, the amount of protein in lymph is (one-half to one-third/one-half to three-quarters)

Explain the concept of herd immunity. What are examples of populations/types of people that cannot receive vaccinations (as opposed to those that choose not to vaccinate)

Herd immunity is that if a certain (usually quite high) percentage of people are vaccinated, then those who are not vaccinated (for a variety of reasons) are protected. It is akin to umbrellas in a crowd. If you are in a crowd and everyone has an umbrella, you will not get rained on because a neighboring umbrella is covering you. Immunocompromised (HIV+, tissue transplant recipient, people receiving some autoimmune treatments) individuals usually cannot be vaccinated, in addition to some vaccines for some very young infants, people with specific allergies to vaccine components and pregnant people with regards to certain vaccines

certain percentage of individuals, unique to each pathogen, be vaccinated to help protect the population from the pathogen

Herd immunity requires that...

True (must be sterile)

Ingredients that impart color, odor, or flavor are prohibited in ophthalmic formulations

False

Intravitreal administration allows for patients to only get a few injections in their lifetime due to slow elimination from the vitreous

What are inactivated and live-attenuated vaccines and what is the difference between the two types?

Live attenuated has some aspect which is lessened or knocked-out to make it mostly non-infective, but it is a live virus which can mutate and replicate in the right conditions. An example of this is Jenner's use of cowpox to vaccinate against smallpox. An inactivated vaccine is heat or chemically killed. All of the elements of the vaccine are there, but the machinery to infect is completely shut-down. An example of this is most of the flu shots given where influenza is chemically inactivated

different

Lymph has the same/different concentration(s) of protein throughout the body.

Overflow of plasma and fluids from the capillaries

Lymph is best described as:

Are open at one end and connected to blood vessels at the other

Lymph vessels are:

open

Lymphatic vessels are an open/closed loop system.

veins

Lymphatic vessels deposits lymph into the veins/arteries

enhances

Modifying the phosphodiester bond into a phosphorothioate bond significantly _____ the stability of nucleic acids in the presence of nucleases

Are generally less immunogenic than viral vectors

Non-viral vectors

D- All the above

Nucleic acids can be delivered A. in their naked form B. in viral vectors C. in non-viral vectors D. All of the above

high

Nucleic acids have (high/low) molecular weight

negative

Nucleic acids have a (positive/negative) charge

less; greater

Osmosis describes how solvents move from areas of (less/greater) concentrated solution to (greater/less) concentration.

Prevent the inward flow of pure solvent across a semi-permeable membrane due to osmosis.

Osmotic pressure is best defined as the pressure required to:

pressure

Osmotic pressure is the amount of ______ required to push a solvent across a semi-permeable membrane to prevent it from leaving one side of the membrane and passing to another.

siRNA

RNA interference can be mediated through

immunogenicity

Sequence optimization and chemical modification of the nucleic acids can partially reduce __________

dissolved

Solvent is defined as the solution in which a substance is ______

True

T/F It is easier for smaller proteins to exit capillaries into the lymph than larger proteins.

False

T/F Once lymph is formed in the extracellular space it does not reenter through the capillaries.

True

T/F Smaller proteins like albumin are more likely to be in lymph than a larger protein like IgG.

True

T/F Some topical delivery system can cause blurring of vision, which should be a consideration when selecting agents for a patient

False

T/F The lymph has a fixed concentration of proteins once it forms and throughout the body

True (Canals in the eye drain into the nasolacrimal duct. Drug can be absorbed across the nasal epithelium into systemic circulation, or it can be swept away via mucociliary clearance and swallowed for GI absorption)

T/F Topically administered ophtalmic drugs can be absorbed systemically

0.9%

Tears are isotonic with a ______ sodium chloride solution.

antisense

The ____ RNA strand guides RISC to the complementary site in the target mRNA and base pairs with the target, complementary mRNA sequence

3

The amount of lymph produced per a day is ______ liters.

30 microliters (commercial eye dropper dispense 25-50 microliters of solution, so a lot of drug can be lost due to overflow)

The blinking eye can accommodate a volume up to

False (30 microliters)

The blinking eye can accommodate a volume up to 50 microliters without spillage

Extracellular fluid

The fluid that surrounds cells outside capillaries is called?

high

The lymphatic system is needed because the pressure in the heart is high/low.

buildup

The lymphatic system is needed because there is a _____ of fluid at capillary beds

down

The number of vaccines generated with Thiomersal as a perservative have gone up/down since 2003

mRNA

This mediates the cleavage and degradation of

D- A and C are correct

To improve the stability of nucleic acids A. Chemical modifications can be made to the backbone B. Chemical modifications cannot be made to the backbone C. Chemical modifications can be made to the sugar D. A and C are correct E. A and B are correct

recognizes double-stranded RNA

Toll-like receptor 3 (TL3)

unstable

Unmodified nucleic acid are _________

antisense

Upon loading into RISC, the passenger strand of the siRNA dissociated from the _____ strand

a causal and temporal relationship between the injury and vaccine to issue a payout; 0

Vaccine court requires (flawless scientific fact/a casual and temporal relationship between the injury and vaccine to issue a payout), yet (0/1,000+) cases have been paid out supporting that autism is caused by vaccines.

does; high

Variance in efficacy (does/ does not) exist across vaccinated populations but most vaccines have (high/low) efficacy across most populations

integrate

Viral vectors can lead to insertional mutagenesis. This is a process where genes (integrate/replicate) randomly into host genes

A high blood pressure pushing out fluid

What best describes how lymph is generated:

30 microliters

What is the maximum volume that can be accommodated by the human eye?

topical

What is the most common route of administration to treat ocular diseases?

Enhance a vaccine's immune response against an antigen

What is the purpose of vaccine adjuvants?

It stimulates an immune response greater than the antigen alone

What is the role of an adjuvant like alum in vaccines, particularly subunit vaccines?

mostly proteins, plasma, and fats from the vasculature and does not include red blood cells

What makes up lymph?

Immunocompromised patients (Healthy middle aged adults not the answer nor infants and children and nor healthy elderly adults)

What populations would be excluded from receiving a live attenuated viral vaccine but could likely receive an adjuvanted protein based subunit vaccine?

Cationic wetting agent (Wetting agents are surfactants... what is the primary role of benzalkonium chloride? Preservative... All opthalmic formulations like respiratory drugs, must be sterile... Multidose containers will contain a preservative. Single-dose containers will not)

What type of chemical is benzalkonium chloride?

cornea

Which anatomical feature is the largest barrier to topical ocular delivery?

D- All of the above

Which components of nucleic acids therapies can induce an immune response A. The non viral vector B. The viral vector C. The SiRNA D. All of the above

Subunit; Killed (whole organism); Live attenuated

Which list places these vaccines in order from safest to least safe?

A vaccine comprised of an influenza virus killed through heat and chemical crosslinking

Which of the following is an example of an inactivated vaccine?

benzalkonium chloride

Which of the following is the most common preservative in ophthalmic formulations?

Topical, Intravitreal, and Oral (You can give drugs orally, IV, or through other systemic routes for treatment of disease in the eye.. Topical delivery is not good for delivery to the posterior segment of the eye. As long as drug can penetrate the cornea via passive diffusion, topical delivery is good for the treatment of diseases in the anterior eye when the targets are right under the cornea.. Must administer drug via a systemic route or via direct injection into the vitreous humor for target in the posterior eye. Direct injection is called the intravitreal route)

Which of the following is/are administration routes for the treatment of ophthalmic disease?

The antigen is not strongly immunogenic because it is only part of a pathogen.

Why do subunit vaccines often include an adjuvant?

The virus changes enough that our immune response from the previous year is not effective

Why is an annual influenza vaccine needed?

Because an ID injection has less space for injection than IM

Why would the ID vaccination have less volume and antigen than an IM vaccination?

Classification of Targeting

a. First order targeting -Systems that deliver the drug to the capillary bed o the tissue b. Second order targeting -Specific delivery of a drug to a special cell type, such as tumor cell, and not to normal cells (antibody is an example) c. Third order targeting -Delivery specifically to the internal or intracellular site of a cell (specific cellular component)

are

siRNA and short oligos (are/are not) recognized by the innate immune system