512 Pharmaceutics Mid 1
90, 99, 99.9% ionized
%ionization of weakly acidic drug when pH is 1, 2, 3 units higher than pKa?
What is the isoelectric point of cysteine? -COOH pKa: 2.05, amine pKa: 10.25, side chain pKa: 8.00.
(2.05 + 8.00) / 2 = 5.03
excipient
. additional substance in a drug products that may be used for a variety of purposes, such as for improving stability, dissolution, manufacturing speed and quality, and flavoring
Enthalpy / Entropy [+or-]? Electrostatic Hydrophobic Chelation Donor-Acceptor (H-bonding)
0 / + + / + - / + - / -
What is the pKa of a weakly acidic drug when, upon dissolving in a solution with a pH of 5.2, the ratio of salt: acid (i.e. A- :HA) is measured to be 0.8:1?
0.0575 M
The E value=0.2 of Drug A means...
0.2 grams of NaCl that exerts the same osmotic pressure as 1 gram of Drug A
How many grams of NaCl must be added to make 80 mL of a 0.75% atropine HCl (E = 0.13) solution isotonic with blood? A: 0.642 g NaCl
0.642 g NaCl
How many milliequivalents of potassium chloride are represented in a 20 mL dose of a 10% (w/v) potassium chloride elixir? MW KCl = 74.5
10% = 10 g/100 mL (10 g/100 mL) * 20 mL = 2 g KCl (2 g KCl) * (1 mol KCl/74. 5g) * (1 Eq KCl/1 mol) * (1000 mEq/1 Eq) = 26.8 mEq
. Water's own dissociation constant, Kw, equals ...?_.
10E-14
What would the rate of dissolution be if the surface area was increased to 2.5 x 102 cm2 ?
12.2 mg/s
Very fine particles would be expected to collect in Sieve No. (10 / 50 / 120)
120
valence number of calcium chloride CaCl2
2
valence number of dibasic calcium phosphate CaHPO4
2
How many milliosmoles of sodium are represented in 1 liter of 3% hypertonic sodium chloride solution (MW 58.5)? Assume complete dissociation.
3% = 3 g / 100 mL (3 g/100 mL) * (1000 mL) = 30 g NaCl (30 g NaCl) * (1 mol / 58.5 g)* (1 Osmol Na)/(1 mol NaCl) * (1000 mOsm/1 Osmol) = 512.8 mOsm
Dr. Jay receives an order for 20 mL of 2% tropicamide ophthalmic solution. The solution must be isotonic. The E value of tropicamide is 0.11. How many milligrams of tropicamide will be needed for a 20 mL dose? How many milligrams of sodium chloride will he need to add to make the 20 mL solution isotonic?
400 mg tropicamide, 136 mg NaCl.
One mole of an element contains...? atoms of that element
6.02E23
If the drug is in a solution where pH equals the drug's pKa, if you decrease pH by 1 unit, __?%_ of the drug will exist as HA and __?%__ as A-.
90%, 10%
capsules Direct compression (tabs) Dry granulation (tabs) Wet Granulation (tabs)
<Common manufacturing technologies> - list 4
Very soluble: >?g/mL slightly soluble: ?-?mg/mL Insoluble: <?mg/mL
>1g/mL 10-1mg/mL <0.1mg/mL
What can we do to change the dissolution rate of a solid drug: Surface Area of Undissolved Solid
>Increase surface area by decreasing particle size. Effective surface area is area in direct contact with water. Reduced particle size leads to increased effective surface area and increased dissolution
Define: • USP • GSE • Ksp • Noyes-Whitney Equation • BCS Biopharmaceutical Classification System • Log P
>United States Pharmacopeia-National Formulary >General Solubility Equation log Sw = 0.5 - [0.01 (mp - 25)] - log Ko/w >Equilibrium constant for the equilibrium between an ionic solid and its saturated solution >dC/dt = [D * A* (Cs - Cb)]/h >Biopharmaceutical Classification System (ClassI&3=high sol / Class2&4=Low sol) >(Concentration dissolved in partition solvent/Concentration dissolved in water)
One of the disadvantages of the co-solvent approach for enhancing drug solubility is: A. The potential toxicity of the co-solvent B. They are complex and slow to formulate and produce C. They cannot be combined with other solubilization techniques
A. The potential toxicity of the co-solvent
Which of the following is not true of cyclodextrins: A. They are inexpensive B. They can increase the rate of dissolution of poorly soluble drugs C. They can be used for taste-masking of some drugs
A. They are inexpensive
1. oral 2. sublingual 3. buccal 4. rectal 5. vaginal 6. intranasal 7. pulmonary 8. ophthalmic 9. topical/transdermal 10.intravenous (IV) 11.subcutaneous 12.intramuscular (IM
A. vagina B. veins C. subcutaneous fat D. mouth (swallowed) E. mouth (inhaled) F. striated muscle G. rectum H. under the tongue I. epidermal surface J. eye surface K. nasal cavity L. between the cheek and gums
flowability
Angle of Repose is a measure of powder's a. solubility b. Chemisorption c. Flowability
methyl/propyl paraben
Anti-oxidants&preservatives
Mg stearate
Antiadherents
Drug Molecules Possessing __?___ are Capable of Chelating Metals
Atoms with lone pairs of electrons_
Which of the following methods would decrease the aqueous solubility of an acidic hydrophilic drug? A. Complexation with a hydrophilic cyclodextrin molecule B. Conversion to a prodrug by adding a lipophilic functional group C. Formation of a hydrochloride salt of the drug
B. Conversion to a prodrug by adding a lipophilic functional group
Cyclodextrins enhance drug solubilization by: A. Self-association and formation of stacking complexes B. Formation of inclusion complexes C. Formation of microemulsions
B. Formation of inclusion complexes
As pH increases, the solubility of basic (amine-containing) drugs generally: A. Increases B. Decreases
B: Decreases
2. A salt is the product of an acid and a ________
Base
Which of the following is generally true regarding making different salt forms of drugs: A. Salts are rarely used with weakly acidic drugs B. Salts are never used to decrease drug solubility C. The smaller the size of the counter-ion, the greater the solubility of the salt
C. The smaller the size of the counter-ion, the greater the solubility of the salt
sodium carboxymethylcellulose
Disintegrants
To which BCS class does a drug with the following properties belong? *The anticipated dose of the drug is 1.4 mg *The drug has a minimum solubility of 8.2 mcg/mL over a pH range of 1-8 *It is estimated that that 1.15 mg of the drug will be absorbed in humans
Dose/Solubility = Dose Volume 8.2 mcg = 0.0082 mg 1.4 mg/ 0.0082 mg/mL = 171 mL Since 171 mL< 250 mL, it is considered "High Solubility" Permeability 1.15 mg/1.4 mg x 100% = 82% Since 82% < 90%, it is considered "Low Permeability" Therefore, this is a BCS Class III compound
List two instruments that can be used to measure interfacial tension
Du Nuoy Ring, Wilhemy Plate
What is the thermodynamic driving force that favors complexation by cyclodextrins?
Entropy ....(?)
-low solubility, dissolution -high melting pt -high stability -low Hardness (compaction behavior, tablet compressibility)
Factors influenced by crystal form? -solubility -melting pt -stability -hardness(compaction behavior, tablet compressibility) -hygroscopicity -color/refractive index..??
A eutectic will form only when the molar ratio of two solids is equal (True / False)
False
If a 5 mg/dL dextrose solution and a 10 mg/dL dextrose solution are placed into two compartments separated by a semi-permeable membrane, dextrose molecules will flow to the less concentrated compartment through a process called osmosis. [T/F]
False
The addition of 10 mg of glucose to 500 mL of normal saline will increase the volatility of the solution. [T/F]
False
add positive and negatives charges together when calculating milliequivalence [T/F]
False
lactose
Fillers/Diluents
pH = pKa + log ([B]/[BH+ ]) pH = pKa + log ([A-]/[HA ])
HH eq for weak base ..for weak acid
-add flavoring -coating (pH sensitive coating)
How to Develop OTD
-mft amorphous form? -mft solid solution? -Hydrate/solvate or salt form? -mft mixture of two solids (form eutectic??) -Co-crystallization(e.g. like w cyclocextrin)=YES
How to improve dissolution and bio availability of insoluble, weak base(w vv low pKa) drug?
Use wetting agent (glycerol)-> contact angle, Use PEG to make solid solution then ground into granules
How to improve dissolution and bioavailability of hydrophobic, large, insoluble drug?
Prussian blue
How to treat Cs and Tl?
less, reduced
If ionized drug reduces passive reabsorption and your drug,weak base, is in alkaline urine(pKa<pH), it result in [less/more] ionization and [reduced/increased] renal elimination.
What is the difference between a solid solution and a solid suspension? (Both for drugs that are poorly soluble and difficult to wet)
In a solid solution, the ASI is dispersed at the molecular level
If BaSO4 is added to water, the equilibrium concentration of Ba2+ in solution is 1.04 x 10-5 M. What is the Ksp value of BaSO4?
Ksp = [Ba2+] [SO4 2- ] = [1.04 x 10-5 M] [1.04 x 10-5 M] = 1.08 x 10-10 M2
The binding of soluble preservative molecules to the surface of particles in a suspension can be quantified by constructing a
Langmuir Isotherm.....[SP]/[S][P], coverage of adsorbate(P) to the adsorbent
6. Surface tension is an interfacial tension that occurs between a ___________ and a __________
Liquid/Gas, surface tension is when cohesive force wins over adhesive force
The log Kow (or log P) can be defined as the...
Logarithm of the octanol-water partition coefficient
What is the possible consequence of the binding of soluble preservative molecules to the surface of particles in a suspension?
Loss of preservative activity (learn this??)
If the Dissociation Constant KD = 1 / KA , then what are the units of KD?
M
289mOsmol/kg
Normal mean osmotic pressure of human
If a USP Type II Apparatus was used to assess the dissolution of a 40 mg furosemide tablet, would sink conditions exist?
Noyes-Whitney Cb = 40 mg/900 mL = 0.044 mg/mL 0.1 Cs = 0.018 mg/mL Sink conditions exist when Cb < 0.1 Cs In this case, Cb > 0.1 Cs Therefore, sink conditions would not exist
Sometimes partition coefficient measurements use unequal volumes of oil and aqueous phases. Why? If, during an experiment to determine the octanol-water partition coefficient of Drug X, there were 320 mg of Drug X in the 10 mL of the octanol layer and 4.2 mg of Drug X in 50 mL of the aqueous layer, what would the Log P of Drug X be?
Octanol: 320 mg/10 mL = 32 mg/mL Water: 4.2 mg/50 mL = 0.084 mg/mL Kow = 32/0.084 = 381 log Kow = 2.5
Aspirin has a pKa of 3.4. What is the ratio of A- to HA in (a) the blood (pH 7.4) and (b) the stomach (pH 1.4)?
Part (a): pH = pKa + log [A-]/[HA] 7.4 = 3.4 + log [A-]/[HA] 7.4 - 3.4 = log [A-]/[HA] 4 = log [A-]/[HA 104 = 10000 = [A-]/[HA] (b) 0.01
What is the difference between solid dispersions (solid solutions & solid suspensions) and co-crystals?
Solid dispersions are physical mixtures of drug and a highly water-soluble carrier (such as sugars, acids, polymers) molecule in microcrystalline form. Co-crystals are composed of the drug and another molecule that is a crystalline solid rather than a liquid (as in crystal hydrates).
List four purposes of excipients.
Stability • Dissolution • Manufacturing speed • Manufacturing quality • Flavoring
The formation of emulsions for enhancement of drug solubilization involves an oil phase, an aqueous phase and a: A. Hydrate B. Surfactant C. Prodrug
Surfactant
Which USP solubility expression would you predict the solubility of a drug with a MW of 322, a logP value of -0.24 and a mp of 112oC to have?
Sw = 0.74 M x 322 g/mole = 238 g/L = 238 mg/mL (freely soluble)
List ten common dosage forms.
Tablet • Capsule • Suppository • Solution • Suspension • Ointment • Cream • Gel • Aerosol
What determines the relative hardness/softness of a gelatin capsule?
The ratio of dry plasticizer to dry gelatin 0.3-1.0 for very hard shell 1.0-1.8 for very soft shell
fraction of unionized, fraction of ionized of weak acid. *Total of the fractions equal 1
Theta HA vs. Theta A-
What is the role of a glidant in a tablet formulation?
To promote powder flowability
Why is MgSO4 (Ksp = 5.9 x 10-3 ) is sometimes added to suspensions of BaSO4?
To reduce the concentration of soluble Ba2+ by the Common Ion Effect
establishing sink conditions in vitro important bc dissolution rate can be affected by sink conditions (Cb<0.1Cs=dissolution rate is directly proportional to the Cs)
USP apparatii are used to determine disintegration and dissolution times. why Sink condition is important for in vitro dissolution test?
How can hygroscopicity be reduced in crystals?
Use a granular form to reduce surface area; add sorbents, e.g., starch; package in Al foil or plastic
What type of intermolecular force drives the attraction of one particle in a suspension to another
Van der Waals forces; Ionic interactions
contact angle with water
Wettability of solid is determines by..
Size • Charge • Lipophilicity
What are three physicochemical properties of a drug that may impact its distribution to a target?
disintegration
What is Breaking down substance into tiny granules or particles? (inc SA)
pH=1/2pKa-1/2Logc 2.7
What is the pH of a 0.5M solution of warfarin, a weak acid with pKa = 5.1?
Under what circumstance would we want to form a eutectic?
When we want to form a lower mp mixture such as in a topical formulation
within cells • embedded in cell membranes • outside of cells in various body fluids
Where are drug targets located?
a. Wet granulation b. Dry nor wet granulation
Which munufacturing technology not suitable when dealing with hydrolyzable API? ..for heat sensible API?
Polymorph slowly changed the crystal form to a more thermodynamically stable form; less soluble(dissolved/bioavailability)
Why was bioavailability decreased for Ritonavir after 2yrs since FDA approval
Can intermolecular forces exist between different solids in a powder mixture?
Yes.
Complexation with _____?____ can enhance the apparent solubility of some hydrophobic drugs
_cyclodextrins
Co-crystal
a crystal containing two components that is not a salt
drug product
a finished dosage form, e.g., tablet, capsule, or solution, that contains a drug substance
The General Solubility Equation uses which of the following parameters to estimate drug solubility? [what is the equation?] a) Log Partition Coefficient (log Kow/Log P) and melting point (mp) b) Solubility Product (Ksp) and melting point (mp) c) Partition Coefficient (Kow) and Dose Volume
a) Log Partition Coefficient (log Kow/Log P) and melting point (mp) log Sw=0.5-0.01(mp-25)-log(Kow)
Which is more soluble, MgSO4 or BaSO4?
a) MgSO4 (Ksp = 5.9 x 10-3 ) (Larger Ksp = greater solubility) b) BaSO4 (Ksp = 1.08 x 10-10)
a) What is the predicted solubility of this drug a new multi-ester prodrug with a MW = 525 and a melting point of 45oC? *When this drug was added to an octanol-water mixture and allowed to achieve equilibrium, the concentration of the drug in octanol was 1,125 times greater than the concentration of the drug in the water phase.* b) What term would you use to characterize the solubility of this drug?
a) log Sw = 0.5 - [0.01 (mp - 25)] - log Ko/w log Sw = 0.5 - [0.01 (45 - 25)] - log (1,125) log Sw = 0.5 - 0.2 - 3.05 = -2.75 Sw = 1.78 x 10-3 M x 525 g/mol = 0.931 g/L ~ 1 mg/mL b) Slightly soluble to very slightly soluble
During tablet dissolution in a USP 2 Dissolution Apparatus, sink conditions exist when: a) the saturation solubility of the drug (Cs) is 10-fold greater than the drug concentration in the bulk layer (Cb) b) the concentration of the drug in the bulk layer (Cb) is greater than the concentration in the diffusion layer c) the dissolution rate is independent of tablet surface area
a) the saturation solubility of the drug (Cs) is 10-fold greater than the drug concentration in the bulk layer (Cb)
Before an orally administered drug can enter the bloodstream, it must be [absorbed/adsorbed] by cells in the small intestines.
absorbed
higher, lower
adhesion have[higher/lower] surface energy and cohesion have [higher/lower surface energy
ΔH ΔS => G?, Spontaneity + / - - / + + / + - / -
always + / Never spontaneous always - / always spontaneous Depends on T / Depends on T/
LADME
an acronym for the processes in drug disposition
route of administration
anatomical pathway through which a drug product may be administered
inactive ingredient
any component other than an active ingredient
drug substance
any component that is intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the structure or any function of the body, but does not include intermediates used in the synthesis of such ingredient
active pharmaceutical ingredient (API)
any component that is intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the structure or any function of the body, including components that may undergo chemical change in the manufacture of the drug product and be present in the drug product in a modified form
The amount of acid/base needed to change the pH of 1 liter of solution by 1 pH unit is called __?
buffer capacity
For the purposes of assigning drugs to the Biopharmaceutical Classification System (BCS), a drug substance is considered to have "High Solubility" when the highest dose strength is soluble in: a) when the extent of absorption in humans is determined to be > 90% of an administered dose b) greater than 250 mL over a pH range of 1.0 - 7.5 c) less than 250 mL over a pH range of 1.0 - 7.5
c) less than 250 mL over a pH range of 1.0 - 7.5
Is Kayexalate®, which is used as a potassium binder in acute and chronic kidney disease for people with hyperkalemia, an anion or cation resin?
cation. (cation exchange resin= acidic resin, anion exchange resin= basic resin)
Milliequivalence takes into account the number of...? associated with an ion
charges_
Hydrate
crystal structure incorporating either stoichiometric or non stoichiometric amounts of water
solvate
crystal structure incorporation either stoichiometric or non-stoichiometric amounts of solvent
Calculate the dissolution rate of a hydrophobic drug formulation having the following physicochemical characteristics: • Surface area = 2.5 cm2 • Saturated solubility = 0.35 mg/mL (at room temperature) • Diffusion coefficient = 1.75 x 10-5 cm2 /s • Thickness of diffusion layer = 1.25 μm • Concentration of drug in bulk = 2.1 x 10-4 mg/mL
dM/dt = {(1.75 x 10-5 cm2 /s)(2.5 cm2 )( 0.35 mg/cm3 - 2.1 x 10-4 mg/cm3 )} / 1.25 x 10-4 cm [Note: I converted 1.25 mm to 1.25 x 10-4 cm (1 μm = 1 x 10-4 cm)] dM/dt = 0.122 mg/s
What can we do to change the dissolution rate of a solid drug? (think Noyes-Whitney equation)
dM/dt =(D/h)S (Cs-Cb)
A high concentration of chloride ions in the stomach is most likely to ______________ the solubility of the hydrochloride salt of a drug. a) increase b) decrease c) have no effect on
decrease
Adhesion is the attraction between molecules of [same/different] substances
different
Polymorphs
different crystal structures(forms) in which a compound can crystallize
two solvents and surfactant
emulsion needs..?..solvents and ..?..
When solute and solvent form attractive forces, this is an (exothermic / endothermic) process that (absorbs / releases) energy
exothermic, releases
A 2018 Guidance Document from FDA declared that co-crystals are to be considered as intermediates and not as APIs (true / false)
false
If acetic acid (pKa 4.75) is dissolved in a solution with pH 7.8, what is the fraction of ionized and unionized acetic acid?
fraction ionized = 0.999113, fraction unionized = 0.000887
high density and low porosity
free flowing
The 4 colligative properties are..
freezing point depression_, __boiling point elevation__, __vapor pressure lowering_, __osmotic pressure
Food and Drug Administration (FDA)
government organization responsible for protecting the public health by ensuring the safety, efficacy, and security of human and veterinary drugs, biological products, and medical devices; and by ensuring the safety of our nation's food supply, cosmetics, and products that emit radiation
1. An amorphous solid has (greater / poorer) solubility than crystal forms.
greater
lipophilic 0<logp<3
higher log p(log Kow)...means... optimal range of log P is...
If the pH of the solution begins much lower than an acidic drug's pKa, but is then titrated so that pH approaches the pKa, the percent ionization (increases / decreases)
increases
A drop of water placed on the surface of a very hydrophilic drug will form a contact angle that is (greater than 90 / less than 90 )
less than 90
A No. 2el capsule holds a greater / lesser volume of powder than a No. OO capsule (assume equal powder density).
lesser
What does each letter in "LADME" stand for?
liberation, absorption, distribution, metabolism, excretion
In a suspension, where we see [liquid-liquid/liquid-solid/solid-gas] interfaces, what do you think would happen if the cohesive forces between the particles was greater than the adhesive forces between the particle and the solvent?
liquid-solid, Particle aggregation
What are the metabolic organs? Which is/are the primary metabolic organ?
liver (primary), intestinal epithelium, kidneys, lungs, skin, placenta
unionized, neutral compounds have (higher / lower) solubility in a polar solvent
lower
A buffer at a given concentration will have a (maximum / minimum) buffer capacity when the ratio of base to acid is 1:1
maximum
When calculating the isoelectric point of a zwitterion with only 1 positive and 1 negative charge, you will take the (sum / mean) of the pKa's
mean
drug target
molecule or structure that is linked to a particular disease
Which two routes of administration are most commonly used for the systemic administration of drugs?
oral and intravenous
Crystal
orderly arrangement of molecules and atoms held together by non-covalent interactions. -packed in a ordered way to minimize free volume,(3D periocity)
Several methods for enhancing drug solubility are available:
pH adjustment • Prodrugs • Co-solvents • Salts, solvates/hydrates, co-crystals • Complexation (cyclodextrins) • Surfactants (emulsions)
salt
product of the reaction of an acid and a base
Drug dissolution
rate determining step for absorption of drugs?
liberation
release of a drug from its dosage form
excretion
removal of drug from the body
What are the major and minor excretory pathways?
renal (primary), biliary, saliva, sweat, tears, breath, breast milk
cation
salts of acidic drugs (counterion)?
Cohesion is the attraction between molecules of [same/different] substances
same
Micromeritics / powders
science of particels and technology of small particles that has many applications. In manufacturing tablets and capsules, control of particle size, shape and porosity (SA) are essential in achieving necessary flow properties and proper mixing granules and powders.
oil/ Powder
soft gelatin capsules for.. and Hard gelatin caps for...
Amorphous form
solid that does not give a distinctive powder X-ray diffraction pattern -short range order -Higher free energy -(higher E state than crystalline) -Thermodynamically metastable with tendency to revert to crystalline form -Grinding(particel size reduction) can lead to formation of this material
sublimation
solid to vapor phase direct transition is called.... and is sometimes hazardous to handle
Dialysis is the movement of ...?.. across a semipermeable membrane
solute
More rings [stronger/weaker] chelation with metal ions? What is the driving force for this chelation to occur?
stronger., Macrocyclic Effect
strength
the amount of drug substance contained in, delivered, or deliverable from a drug product
drug disposition
the different processes that can affect the fate of an administered drug product, before and after the drug's entry into the systemic circulation
manufacturing
the mass production of drug products that have been approved by the Food and Drug Administration (FDA)
active moiety
the molecule or ion, excluding those appended portions of the molecule that cause the drug to be an ester, salt (including a salt with hydrogen or coordination bonds), or other noncovalent derivative (such as a complex, chelate, or clathrate) of the molecule, responsible for the physiological or pharmacological action of the drug substance
absorption
the movement of a drug from its site of administration to the bloodstream
distribution
the movement of a drug from the blood and various tissues of the body
dosage form
the physical manifestation containing the active and inactive ingredients that delivers a dose of the drug product
compounding
the process of combining, mixing, or altering ingredients to create a medication tailored to the needs of an individual patient
bioavailability
the proportion (percent or fraction) of an administered dose of unchanged drug that reaches the systemic circulation
pharmacokinetics
the science of the kinetics of drug absorption, distribution, and elimination
biopharmaceutics
the study of the effects of physicochemical properties of the drug and the drug product, in vitro, on the bioavailability of the drug, in vivo, to produce a desired therapeutic effect
metabolism
transformation of drug into substances that are more easily excreted
The crystalline nature of a solid drug may be changed by grinding/particle reduction (true / false)
true
Buffers are mixtures of a (weak acid / strong acid) and its conjugate base
weak acid
Dissolution (RDS)
what is substance going into solution
a.)weakly acidic drug, salt of weak base w/ strong acid b.) weakly basic drug, salt of weak acid w/ strong base c.) salt of weak acid w/ weak base
which type of drug can be used for these equations? a.) pH=1/2pKa-1/2Logc (name 2 types) b.) pH=1/2pKw+1/2pKa+1/2Logc (name 2 types) c.) pH=1/2pKw+1/2pKa+1/2LogpKb
Needle-shaped and finer particles tend to flow (better / worse) than spherical powders
worse
The isoelectric point is the pH where an __?__ molecule has no net charge
zwitterion
List six physicochemical properties of a drug that may influence its disposition.
• solid states properties • ionization • solubility and dissolution • partition coefficient • mass transport and membrane passage • complexation and protein binding
