PHA 317 Comprehensive Review For Final
Shelf-life
-For pharmaceutical products, is the time duration after manufacture until which the critical quality attributes of the product are within acceptable limits -For API, it is the time until the concentration of the API is below defined acceptable minimum levels
1 centipoise is equal to?
.01 poise
viscosity of an unknown liquid is .580 cp at 25 C and the denisty is .858 g/cm^3. what is the kinematic viscosity of that unknown liquid?
.676 centistokes
1 centipoise is equal to
0.01 poise
What is the ratio of ephedrine to ephedrine HCL in the intestinal tract at ph 8
0.025:1
The time taken for 5% of a drug to decompose by first order kinetics is
0.051/k1
Time taken for 5% of a drug to decompose by first order kinetic
0.051/k1
the following data were obtained for the hydrolysis of homatropin which follows first order kinetics in 0.226mol/L HCL at 90C
0.053hr
What is the normality of the 100mL solution containing 585 mg of NaCl in water
0.1N
Fickian (first-order) release
0.43<n<0.5
Anomalous release
0.5<n<0.89
Viscosity of an unknown liquid is 0.580 cp at 25 degrees celsius and the density is 0.858/cm cubed. What is the kinematic viscosity of the unknown liquid
0.676 centistrokes
What is the remaining concentration A in mg/ml of a drug inital concentration a0=7mg/ml after atime equivalent to 3 half lives assuming that the decompositon follows first orders kinetic
0.875
What is the remaining concentration in mg/ml of a drug (initial concentration. a= 7 mg/ml) after a time equivalent to 3 half-lives assuming that the decomposition follows first order kinetics
0.875
Case II (0-order release, where transport is entirely controlled by polyer chain relaxation)
0.89<n<1
when one mole of a solute is dissolved in one liter of a solution, the concentration of the solute is termed as
1 molar
What is the stomach's ph range
1 to 3.5
What is the stomachs ph range
1-3.5
10g of sucrose is dissolve in 500 ml of water at 25C. what is the osmotic pressure of the solution?
1.43 atm
when atropine was added to a mixture of water and octanol at 25C its concentration in octanol and in water was 3.96 and 2.2mg/ml respectively. what is partrition coeffcient P of stropine in this system?
1.8 octanol/water
Spans sorbitans esters have HLb values from
1.8-8.6
The half-life of a drug in a solution is 30 minutes. What would be the concentration o the drug in the solution after 90 minutes?
12.5%
calculate the solubility of ibuprofen a weak acidic drug in a medium mimicking intestinal fluid which pH is 8
1262 mg/ml
the following data were obtained for the hydrolysis of homatropin (which follows first order) in .0226 mol/L HCL at 90C
13.2h
An increase in temperature by 10C near room temperature is known to cause
2-4 Fold increase in reaction rate for many reactions
compute the vapor pressure of water at 125 C. the vapor pressure of water at 100 C is 1 atm and Delta H is 9720 calories/mole
2.27atm
the require HLB (RHLB) value for making an o/w emulsions is 10.8 calculate the amounts of tween 20 ( HLB value 16.7) and span 80 (HLB value 4.3) for making 5g of required emulsifier
2.6 T20 and 2.4 S80
What is the ph of a buffer containing .1M acetic acid and .08M sodium acetate
2.9
150. The initial concentration of active principle in an aqueous preparation was 5.0 x 106-3 g/ml. After 10 months the concentration was found to be 4.2 x 10^-3 g/ml. the drug is known to be ineffective after it has decomposed to 70% of its original concentration. Assuming that decomposition follows first order kinetics, calculate the expiry date of the drug preparation
20.5 months
The initial concentration of active principle in an aqueous preparation was 5.0 * 10^-3 g/ml. After 10 months the concentration was found to be 4.2 * 10^-3 g/ml. The drug is known to be ineffective after it has decomposed to 70% of its original concentration. Assuming that decomposition follows first order kinetics, calculate the expiry date of the drug preparation.
20.5 months
110. When 1ml of a 0.009% (w/v) solution of stearic acid (Mol. Wt. 284.3) dissolved in a volatile organic solvents is placed on the surface of water in a trough, the solvent evaporates off, leaving the stearic acid spread over the surface as an insoluble monolayer film. If the surface area occupied by the film is 420 square cm, calculate the area occupied by each molecule of stearic acid in the film
219.89 x 10^-17 cm^2
half life of a drug in a solution is 30 min. what would be the concentration of the drug in the solution after 90min?
25% initial
The contents of an aerosol are at a pressure of 2 atm at 25C. what happens to the pressure of the aerosol when it is stored at 200C. given volume is .05L
3.2 atm
A plastic material has a yield value of 3000 dynes cm^2. at shearing stress above the yield value F was found to increase linearly with rate shear G. If the rate of shear G was 100 sec when F was 6000 dynes cm^-2 what is the plastic viscosity?
30 poises
What is the minimum time required for IV injection of a 22mg dose of a poorly water soluble drug to ensure that precipitation does not occer. given that solubility of drug in plasma is .7mg/ml and venous flow rate is 50ml/min
38 secs
Brush border
3mm-thick mucopolysaccharide coating on entire GIT that serves as a mechanical barrier
What is the ph buffer containing 0.1-M acetic acid and 0.08 M sodium acetate
4.7
When a capillary tube is benzyl benzoate, the liquid rose to a height of 1.63cm at 25C the inside diameter of the capillary is .1cm and the density of benzyl benzoate is 1.112 g/cc. what is the surface tension of benzyl benzoate?
44.45 dynes/cm
Ph range of duodenum is
5 to 7
The pH range of the duodenum is
5-7
Calculate the energy of a radiation of wavelenth 4000 angstroms
5x10^12 ergs
one mole of any substance contains an avogardo number of molecule which equals
6.023 x 10^23
What is the osmotic pressure of a strong electrolyte solution of 1.5 molar concentration at a temperature of 298K the ivalue is 1.65
60.48atm
You will use the surfactant having HLB values shown below to prepare an emulsion of olive oil in water
9-15
Weak basic drug has a pka 4.8 in urine with a ph of 5.8 how much % of this medication would exist in its original ionized form
90.09%
human plasma contains about 5 meq/liter of Ca2+ ions. How many milligrams of CaCl22h20 are required to prepare 250ml of a solution equal to Ca2+ to human plasma
91.88mg
142. The driving force for processes to occur is a. All systems spontaneously move towards lower free energy and higher entropy b. All systems spontaneously move towards lower free energy and lower entropy
A
Hixson crowell cube root law is capable of determining dissolution rate when a. The shape of the dissolving particle is uniform and does not change during dissolution b. The shape of the dissolving particle is random irregular and does not change during dissolution
A
Minocycline and doxcycline have a greater log P value than other tetracycline. Which is correct. a. Only minocycline and doxycycline pass through blood brain and blood ocular barriers while other tetracycline do not b. Minocycline and doxycycline pass through blood brain barrier but not through blood ocular barrier c. Minocycline and doxycycline pass through blood ocular barrier but not through blood brain barrier
A
Solubility among isomers increases with a. Decreasing boiling and melting point for liquid and solid b. Increasing boiling and melting point for liquid and solid
A
when a capillary tube is placed in a liquid the level of liquid in the capillary tube fell to a lower level than that of the liquid outside the tube. this is because a. The cohesive forces between the liquid liquid are greater than the adhesive forces between liquid glass b. The adhesive forces between the liquid liquid are lower than the cohesive forces between liquid glass c. The adhesive forces between the liquid glass and the cohesive forces between liquid liquid are equal d. The adhesive forces between the liquid glass are greater than the cohesive forces between liquid liquid
A
2-4
A 10 degree Celsius increase causes a reaction rate to increase by _______ fold
You are the drug information pharmacist in your state, and a few pharmacy interns are working under your supervision. You receive a phone call from the local hospital emergency center regarding a case of acetaminophen poisoning. The patient has ingested 20 Tylenol caplets. What information do you need to collect to provide a better understanding of the dose of activated charcoal needed for this patient?
A 50 g dose of AC has an adsorp- tive surface area equivalent to the surface area of seven football fields. Super-activated charcoal may have a surface area of 2,800#3,500 m2/g. Activated charcoal acts as an adsorbent because of its higher surfaces by weak intermolecular (Van der Waals) forces. For 1 g of drug, you need 10 grams of AC. In this case, 20 Tylenol caplets contain 10 g of active drug. Therefore, you need at least 100 g of AC for this patient.
138. Lineweaver burke equation for an enzymatic reaction is useful for a. Determining the constant km in michaelis menton equation b. Determining the constant vmax in michaelis menton equation c. Determining only the constant km or vmax but nto both simultaneously in michaelis menton equation
A and B
58. A atypical IR spectrum can be broadly divided into two parts a. Wavenumber range of 1450 - 600 cm^-1 is called finger print region because this is unique for a specific substance b. Wavenumber range of 4000 - 1450 cm^-1 is called group frequency region because this is unique for a specific functional group present in a substance c. Wavenumber range of 4000 - 1450 cm^-1 is called finger print region because this is unique for a specific substance d. Wavenumber range of 1400 - 600 cm^-1 is called group frequency region because this is unique for a specific functional group present in a substance
A and B
Some Potential applications of mass spectroscopy a. Mass spectra are useful in proving the identity of a compound and establishing its structure b. Mass spectra are useful in proving the identity of a compound but not in establishing its structure c. Mass spectrum provides an exact molecular weight and molecular formula of a substance d. Mass spectrum provides and exact molecular weight of a substance but not its molecular formula
A and C
84. Below are some statements about BCS class I drugs a. Class I drugs are well absorbed and are affected by a limited set of interactions that alter drug absorption b. Interactions that delay gastric emptying will delay absorption of these drugs c. Gastric emptying rate has significant effect on absorption of class I drugs d. Gastric emptying rate does not affect absorption of class I drugs
A and c
absorption
A bulk phenomenon; passage of one substance into/through the bulk of another medium (will saturate the whole medium)
cup-and-bob viscometer
A device that measures the viscosity of non-Newtonian fluids; can operate at multiple rates of shear
Freundlich
A quantitative measure of physical adsorption that is only uses with gas-solid systems; better with lower concentration
Indicate which of the following statement is correct? a. When a solution is contained within a semipermeable membrane and separated from the solvent, the solvent will not pass across the membrane into the solution b. A solution that has a greater osmotic pressure than plasma is said to be hypertonic c. The chemical potential or concentration of solvent molecule in the solution is greater than that in pure solvent d. When red blood cells are immersed in a hypotonic solution they will shrink
A solution that has a greater osmotic pressure than plasma is said to be hypertonic
adsorption
A surface phenomenon; adhesion of molecules of a liquid or gas to the surface of a solid or sometimes a liquid
Thixotropic flow
A type of Non-newtonian flow exhibited by shear thinning systems when the shear is applied, resistance to flow progressively decreases. These substances will retain their "thinned" state even once the shear is removed
140. A base catalyzed hydrolysis of an ester such as chloramphenicol palmitate can exhibit a. A second order kinetics only if teh concentration of both ester and base are changing b. A pseudo first order kinetics if the concentration of the hydroxyl ion is maintained constant c. A pseudo zero order kinetics if the concentration of both ester and base are maintained constant d. A first order kinetics if teh concentration of teh hydroxyl ion is maintained constant e. A zero order kinetics if the concentration of both ester and base are maintained constant
A, B, C
82. Below are some statements about BCS class III drugs a. Intestinal membrane absorption is the rate limiting step In the absorption of class III drugs b. Class III drugs are better absorbed in the upper part of small intestine c. Any meal co administered with class III drugs decreases their absorption proportionately to fat content of the meal d. Any meal co administered with class III drugs decreases their absorption which is not influenced by the fat content of the meal
A, B, D
Commonly employed adsorbent as an antidote is
Activated charcoal
Langmuir
Adsorption isotherm; a quantitative measure of physical adsorption that can be used with gas-solid or liquid-solid systems; better with higher concentration
59. Below are some potential applications of UV visible spectroscopy a. The concentration of a protein solution can be calculated if its amino acid sequence and molecular weight is known b. The presence of RNA as impurity in a DNA sample can be determined by the ratio of its absorbance at 260 nm and 280 nm c. The extent of ionization of an acid can be easily determined
All
69. Equilibrium is involved in the following processes playing an important role in pharmaceutics: a. Ionization of weak acidic or basic drugs b. Partition coefficient and lipid solubility of a drug c. Saturation solubility d. Diffusion and dissolution of drug i. A and c are correct ii. A and d are correct iii. All are correct iv. B and c are correct
All
98. Knowledge and understanding of equilibrium solubility of a drug is absolutely essential because it plays a critical role in a. Drug discovery process b. Drug formulation process c. Drug dissolution in gastrointestinal tract d. Drug absorption
All
99. A concept of the partition coefficient is involved in following areas of pharmaceutical sciences a. Preservation of oil water systems b. Drug action in non-specific site c. Absorption and distribution of drugs throughout the body
All
Following are some approaches to prevent the oxidative degradation of drug a. Using an initiation inhibitor such as EDTA (ethylene diamine tetraacatic acid) b. Using colored glass containers c. Using chain breakers such as alpha tocopherol d. Using oxygen scavenger such as sodium metabisulfite and ascorbic acid
All
the forces that binds molecules includes which? repulsive and attractive forces van der waals ion-dipole and ion induced dipole hydrogen bonds
All
Although NMR spectroscopy has intrinsically low sensitivity, it has may advantages as shown below. a. The detection of decrease in phosphocholine level tumor cells b. The detection of decrease in urate oxidase level may indicate efficacy of antmicrobial agents against Aspergillus nidulants c. The detection of decrease in urine hippurate and or increase in plasma alanine level may indicate an increase in hepatic insulin sensitivity
All correct
london
Also called dispersion forces, caused by random fluctuations in electron cloud, induced dipole-induced dipole
glass is an example of
Amorphous solid
Ultra-filtration
An example of diffusion in pharmacy, low temperature and pressure are used to remove water more easily from a preparation
Lyophilization (freeze-drying)
An example of diffusion in pharmacy, typically used with enzyme preparations that cannot be heated to remove water
temperature
An increase in _________________ can lead to a decrease in adsorption---> decrease in CMC---> increase in micelle size, and an increase in solubilization
Rule of 5
Any combination of two of these factors can result in poor intenstinal absorption: -MW > 750 Da -#H-bond donors > 5 -#H-bond acceptors > 10 -Calculated logP > 5
Below are some statements about BCS Class II drugs
Any interaction that increase drug solubility and dissolution rate in the gastrointestinal tract will exert a positive effect on the gastrointestinal drugs The absorption of this class of drugs is often enhanced in proportion to the fat content of the co-administered meal The antifungal drug griseofulvin and the cardiac glycoside drug digoxin are examples of Class II drugs
Drug-excipient interaction can be characterized by IR spectroscopy by
Appearance of a new peak Disappearance of a peak Shifting of a characteristic peak Broadening of a peak Alteration in intensity of a particular peak
Under which situation will the viscosity of oil increase
As temperature decreases
You are a third year pharmacy student in a reputed school of Pharmacy. You received a call from your friend who is also a final year Chemistry student on an OTC medication. He usually stores all his medicine in a medicine cabinet in his apartment bathroom. Recently while opening his aspirin tablets from the bottle he saw something unusual. There are some white crystals like material on the tablet surface and he also gets the smell of vinegar from the bottle. His questions to you are: Is it safe to use this medicine? If not, then why?
Aspirin, or acetylsalicylic acid, can undergo a hydrolytic degradation in the presence of moisture to form salicylic acid and acetic acid (The vinegar smell is possibly coming from acetic acid. The white crystal-like material is pos- sibly due to salicylic acid, one of the toxic degradation products of this drug. So the recommendation is not to take this medication any more. Doing so may cause gastric irritation and ulcer.
surface tension
At any temperature, is defined as the force per unit length (usually dynes/cm) that has to be applied parallel to the surface to counterbalance the net inward pull of a liquid at the surface
130. In a zero order reaction a. The half life is equal to 0.693/k b. The unit of k0 is concentration/time c. A plot of the amount remaining as ordinate against time abscissa is linear with a slope of 1/k
B
In a zero order reaction a. The rate of decomposition is dependent on teh concentration of one of the reactants b. The rate of decomposition is independent on the concentration of any of the reactants c. A plot of the amount remaining as ordinate against time abscissa is linear with a slope of 1/k
B
Which of the following is not correct according to pH partition Hypothesis on Drug absorption a. Un ionized form of acidic or basic drug is preferentially absorbed b. Weak acidic and neutral drugs may be absorbed from the stomach, but basic drugs are not c. The rate of drug absorption and amount of drug absorbed are related to its oil water partition coefficient d. Most drugs are absorbed by passive diffusion e. Weak basic and neutral drugs may be absorbed from teh stomach, but basic drugs are not
B
when chloroform and acetone are mixed together, their total vapor pressure is less than calculated by using Raoults law. Which one of the following is the correct explanation for it. a. This is an example of positive deviation from raoult's law b. This is an example of negative deviation from roult's law c. The adhesive forces between chloroform and acetone is greater than cohesive forces among chroform or acetone molecules d. The adhesive forces between chloroform and acetone is less than cohesive forces among chloroform or acetone molecules
B and C
Class II
BCS class; high permeability and low solubility; griseofulvin and digoxin; increased solubility with food intake (inc. stomach volume) and slower gastric emptying rate
Class I
BCS class; high permeability and solubility; APAP, valproic acid, ketoprofen, dysopyramide, verapamil, metoprolol
Class IV
BCS class; low permeability and solubility; HCTZ, bifonazole
Class III
BCS class; low permeability high solubility; cimetidine, ranitidine, acyclovir, neomycin, atenolol, captopril; faster gastric emptying helps drug to reach duodenum where its better absorbed
The shifting of peak of maximum absorption towards longer wavelengths in a spectrum is called
Bathochromic or Red Shift
The shifting of peak of maximum absoprtion towards longer wavelength in a spectrum is called
Bathochromic or red shift
UV absorption spectroscopy can be used for detecting impurity in a substance. Which one of the following is correct about the presence of benzene as impurity in cyclohexane
Benzene can be detected in cyclohexane because it absorbs at 255nm while cyclohexane absorbs at 200nm
156. The release of a drug from a matrix system occurs by a. Diffusion from the matrix system b. Erosion of the matrix system
Both
Activated charcoal is used as an antidote in drug poisoning because a. The adsorption by activated charcoal prevents bioabsorptio by the gastrointestinal tract b. The adsorption by activated charcoal causes elimination of drugs from the tissues into the gi tract by a process known as gastrointestinal dialysis
Both
Following are the steps involved in the process of determining shelf life or expiration date of a drug a. Reaction rate constant, k , is determined at various elevated temperatures b. A plot of log k vs 1/T will be a straight line which can provide the value of k at room temperature
Both
The plasma level of an orally administered tablet depends on a. Rate of tablet disintegration b. Rate of dissolution of the drug
Both
The brush boarder coats the entire length of the stomach as well as small and large intestine which is consisted of
Both villi and microvilli
62. Which one statement is correct? a. Ionized drugs are useful for optimum therapeutic effect b. Un ionized drugs are useful for optimum therapeutic effect c. Either ionized or unionized drugs could be useful for optimum therapeutic effect depending on site of pharmacological action
C
66. The biological membrane is covered on both side by lipid layers which are interrupted by water filled pores. Which of the following statements is correct? a. The size of the hydrophilic drug molecules must be greater than 4 angstrom to pass through a biomembrane easily b. Just on the basis of molecular size, nothing can be predicted about the transport of a hydrophilic drug across a biological membrane c. The radius of the aqueous pores on biomembrane is approximately 4 angstrom, therefore, any hydrophilic drug smaller than 4 angstrom can get transported through it easily d. The water filled pores on biological membrane has nothing to do with cellular transprot of drugs
C
Debye (=3.33E-30 C*m)
CGS unit of dipole moment
Liso
Change in temperature brought about by 1 M drug soln
Chromophores and auxochromes can be differentiated on the basis of the following statement
Chromophores are a group of atoms which absorb efficiently radiation of a characteristic wavelength where auxochromes do not have their own characteristic absorption peak but maximizes the absorption capacity of the chromophores they are attached to
Below are some statements about BCS Class I drugs
Class I drugs are well absorbed and are effected by limited set of interactions that alter drug absorption Interaction that delay gastric emptying will delay absorption of these drugs Gastric emptying rate has significant effect on absorption of Class I drugs
vdW's forces
Consist of Keesom's forces, Debye forces, and London dispersion forces
A study reported in the British Journal of Dermatology suggests that ointment is evenly spread on the skin as compared to creams and solutions. Ointment showed an even spread to the applied areas. Cream, low-viscosity cream, and solution showed poor spreading, resulting in an uneven distribution of dose (lower dose in the periphery). Can you explain the reasons?
Creams and solutions have some dis- advantages because rapid evaporation (alcohol/water), which is measured as cooling, of formulation influences spreading, resulting in an uneven distribution of drug on the applied surface. Ointments, on the other hand, distribute and spread well to the applied area. The presence of surfactants also helps in spreading because they reduce the contact angle. Therefore, patients should be advised to apply creams and solutions to multiple sites and to spread them quickly.
Paclitaxel is an anticancer drug which is solubilized by using a surfactant named
Cremphor el
Fick's second law of diffusion
Deals with changes in concentration of diffusant in a given region of barrier as a function of time. Answers the question: "At a given point and time, what's the drug's concentration?"
Solubility among isomers increase with
Decreasing boiling and melting point for liquid and solid repectively
v-value
Defined as 0.3 g of drug when dissolved in X mL of water will be isotonic
E-value
Defined as 1 g of drug will have osmotic pressure of X g NaCl
Driving force for diffusion
Defined as the difference in relative humidity between the head space in the bottle and the outer environment
Half-life
Defined as the time required to decrease the [reactant] to 50% of its initial concentration
Reaction order
Defined based on the rate equation obeyed and is considered a kinetic property of the process; sum of exponents of molar concentration of reactions affecting the rate of a rxn
Rate (or speed of a process)
Defined by the rate at which the concentration of species undergoing change decreases or the concentration of the resulting species increases with time
There are two commonly used scales for measuring chemical shifts in an NMR spectroscopy called Delta and Tau scales which are related by
Delta = 10 - Tau Tau= 10 - Delta
there are two commonly used scale for measuring chemical shifts in an NMR spectroscopy called Delta and Tau scales which are related by
Delta= 10-tau Tau=10-Delta
Following are some statements about NMR spectroscopy
Different protons exist in different environemtns and thereby possess different magnetic field strength
Following are some statements about nuclear magnetic resonance spectroscopy
Different protons exist in different environments and thereby possess different magnetic field strength
Increasing which of the following will increase permeability of a molecule across a biological membrane
Diffusivity of the molecule
Systems which increase in volume when sheared are
Dilatant
The concept of partition coefficient applies only to
Dilute solutions
the concept of partrition coefficient applies only to
Dilute solutions
collision diameter
Distance at which the attractive & repulsive forces balance eachother
Maxwell-Boltzmann
Distribution that describes that at lower temperatures, there will be more molecules occupying energy states lower than the activation energy than at higher temperatures
For Newtonian fluids, if the rate of shear is increased two times from its original value while the viscosity remains constant. What change could you expect in shearing stress of that liquid
Double it's original value
Osmotic pump matrix
Drug and osmotic agents reside in separate compartments, drug is released by osmotic pressure developed in the osmotic compartment; suitable for high and low solubility drugs; 0-order release
Knowledge and understanding of the equilibrium solubility of a drug is absolutely essential because it plays a critical role in
Drug discovery process Drug formulation process Selection of a dosage form for a drug Drug dissolution in the gastrointestinal tract Drug absorption
Splitting of a NMR peak occurs due to
Effect of neighboring protons
A matter that exhibits plastic flow, below its yield value would behave as
Elastic flow
Noyes-Whitney
Equation that describes the rate of drug dissolution dC/dt=(DS/Vh)(Cs-C)
Van't hoff
Equation that gives the osmotic pressure caused by nondissociating solute in solution
Inert (insoluble) matrix
Ethyl cellulose, methylmethacrylate, polyvinyl acetate are used for making this matrix. Drug and soluble excipients dissolve forming channels called diffusion pathways through which drug is slowly released. Modeled by Higuchi eqn., sqrt(t) v. drug release (Q) is a straight line. Increased torturosity (channel curviness) decreases rate of drug release
Perfume
Example of concentration-dependent mass transfer in gases
Dialysis
Example of concentration-dependent mass transfer of solute across a membrane
Osmosis
Example of concentration-dependent mass transfer of water across a membrane
Which one of the following facts are correct with respect to thixotropy
Exhibited by shear thinning systems, such as pseudoplastic and plastic liquids Can be defined as an isothermal and comparatively slow recovery, on standing of a material, of a consistency lost through shearing Behavior is useful for many pharmaceutical preps (suspensions)
Hydrophilic (swellable) matrix
Exhibits an initial burst of drug release; polymers dissolve and form a viscous gel layer surrounding the drug to control its release; a combination of dissolution, diffusion and erosion processes control this type of release; the higher viscosity grade (MW and c) of polymer, the slower the drug will be released
A solution isoosmotic with blood would be isotonic too
False
Brush border consists of a 3mm thick uniform coating of mucopolysaccharide which is found lining the internal wall of the stomach only
False
Digestion and absorption of foodstuff occurs separately at different times in the small intestine
False
Drugs exhibiting polymorphism or pseudopolymorphism can be differentiated by using IR spectrophotometer
False
For newtonian fluids, the shearing stress decreases when the rate of shear increases
False
Molarity of a solution does not depend on temperature of the solution
False
Polymers in a solution generally exhibit plastic flow
False
Pseudoplatic flow has a yield value
False
Stronger bases like guanethidine are ionized throughout the gastrointestinal tract and tend to be well absorbed throughout the gastrointestinal tract
False
Stronger bases such as guanethidine are ionized throughout the GI tract and tend to be well poorly absorbed throughout the Gi tract
False
The greater the pKa value for an acid, the greater hydronium ion concentration it would produce on being added to water
False
The greater the pKa value, the stronger the acid would be
False
The most stable polymorph is always used for better clinical outcomes
False
Tyrosine and tryptophan are most prominent amino acids capable of producing fluorescence when exposed to radiation of wavelength 190nm
False
drugs exhibiting polymorphism or pseudopolymorphism can be differentiated by using IR spectrophotometer
False
for newtonian liquids, the shearing stress decreases when the rate of shear increases
False
generally apsorption or transport of a drug in ionized form through GI membrane would be more than its unionized form
False
refraction of light is a colligative property
False
the brush border consists of a 3mm thick uniform coating of mucopolysacchride which is found lining the internal wall of stoomach only
False
1000
Fluorescence is _______x times more sensitive than UV-vis; measures two similarly high signals against a low background, instead of measuring high signal and a low signal
What will be the effect on flux if the concentration gradient of a drug across a membrane would increase two fold
Flux would double
A community pharmacist engaged in compounding is preparing some Nystatin popsicles using the same recipe for drug, water, coloring agent, flavoring agent, and sugar as a sweetener as used previously. To his utter surprise, when he opens the freezer, he finds the batch he made last night has not solidified. Rechecking the calculation also reveals that all the weights of materials and volumes of solvents used were correct. Can you establish a cause of this problem?
From the colligative properties, you know that the presence of salt decreases the freezing point of water. Because the pharmacist used the right amount and previously had success in making Nystatin popsicles, it could be some extra salt that might be causing this problem
zero, first
Hydrolysis of a poorly soluble ester suspension is pseudo-_______-order reaction (drug dissolution and degradation), until all drug has been dissolved (and is no longer in XS) then becomes _____-order
Initial burst release is observed for which of the following matrix-based controlled drug release system
Hydrophilic or swellable matrix systems
Which of the following is NOT a physiological factor affecting the rate and extent of absorption of drugs through GI membrane
Hypophilicity of a drug
Following are some statements about the effect of neighboring electrons in NMR spectroscopy
If a proton is shielded by the induced magnetic field of the neighboring electrons, it will need greater strength of external magnetic field to flip its direction of orientation
negative
In a real soln, _________________ deviation results from adhesive forces being stronger than cohesive forces
positive
In a real soln, _________________ deviation results from cohesive forces being stronger than adhesive forces
We have 1:1 mixture of a polar and nonpolar solvent. If we add a non-polar drug to this mixture where would you find most of the drug
In the nonpolar solvent
oral rehydration therapy
Includes a mixture of glucose and other electrolytes that don't do anything about the severity of diarrhea but replace the lost fluids, minimizing risk of dehydration
Which of the following does NOT increase aqueous solubility
Increasing the length of a straight chain organic compounds
Below are statements about Class III drugs
Intestinal membrane absorption is the rate-limiting step in the absorption of class III drugs Class III drugs are better absorbed in the upper part of the small intestine Any meal co-administered with class III drugs decrease their absorption proportionately to fat content of the meal
1E-14
Ionic product of water, Kw = _____________ at 25*C
Equilibrium is involved in the following processes playing an important role in pharmaceutics
Ionization of weak acidic or basic drugs Partition coefficient and lipid solubility of a drug Saturation solubility Diffusion and dissolution of drug
Generally, octanol is used as organic phase for determining partition coefficient. However, what other alcohol is also used for this purpose
Isobutanol
It is essential not to overheat cocoa butter, which is used as a suppository base during the preparation of the suppository by fusion method. Such suppositories must be stored in the refrigerator. Why?
It exists in four polymorphic forms, beta Is stable. if oil is heated to the point at which it is completely liquefied (about 35_C), the nuclei of the stable beta crystals are destroyed. These suppositories are stored in a refrigerator to preserve their stable beta polymorphic state.
Although NMR spectroscopy has instrinsically low sensitivity, it has many advantages show below:
It is a non-destructive technique Many samples present in a solution Minimal or no sample preparation is needed
Phenobarbital is a weak acidic drug. What would be its solubility in solvents a (ph7) b (ph8) and c (ph10)
It would dissolve more in C than A or B
Phenobarbital is a weak acidic drug. What would be its solubility in solvents A (ph7), B (ph8), C (ph10)
It would dissolve more in solvent C than A or B
beer lambert
Law that only applies to monochromatic light, states that the absorption is directly proportional to the concentration
hydrophobic
Longer ___________ chain leads to an increase in micelle size and an increase is solubilization
hydrophilic
Longer _______________ chain leads to a decrease in micelle size and an increase in #micelles/vol.
Some of the heat labile drugs are dried by freeze drying and some of the protein and other drug products are kept in the freezer to enhance self-life. Do you agree that these facts are always true? If not then what are the possible factors which might affect stability at these low temperatures?
Low temperature, freeze concentration, and ice formation are the three chief stresses resulting during cooling and freezing. Because of the increase in solute concentrations, freeze concentration could also facilitate second-order reactions, crystallization of buffer or nonbuffer components, phase separation, and redistribution of solutes.
the cyrstalline and amorphous solids are characterized by
Melting point and glass transition respectively
White-vincent
Method of adjusting tonicity by adding water to drugs to make an isotonic soln, follwed by addn of an isotonic diluting vehicle
Micronization
Minimally soluble drugs like chloramphenicol, griseofulvin, and phenacetin can have dramatically increased solubility using this technique
Partition
Movement from higher concentration to lower concentration dictated by the substance's solubility in lipid
surfactant
Must contain both a hydro- and lipophilic group; will be adsorbed at the surface/interface to dramatically reduce surface/interfacial tension
For nitroglycerine (NTG), it is important to counsel patient not to remove tablets from packaging until they actually use the tablets. This is due to what characteristic of NTG?
NTG is susceptible to loss by sublimation at room temperature
If the shearing stress is directly proportional to the rate of shear the liquid exhibits a
Newtonian flow
Benzene is a colorless organic solvent, but nitro benzene is pale yellow liquid while p-hydroxynitrobenzene is bright yellow. The shift in the appearances of color for these substances can be explained on the basis of concept of chromophores and auxochromes. Select the correct example of each
Nitro group is a chromophore and hydroxyl is a auxochrome
Minocycline and doxycycline have greater log p value than other tetracycline. Which of the following statements is/are correct about them
Only minocycline and doxycycline pass through blood brain and blood ocular barriers while other tetracycline does not
Which one of the following properties does not affect absorption of a drug from gastric lumen
Optical rotation
Indicate which of the following is correct about osmosis
Osmotic pressure is proportional to number of ions or molecules of solute dissolved in solvent
Catalyzed
Oxidation due to free radicals is classified as _______________________.
Uncatalyzed (auto-oxidation)
Oxidation due to molecular O2 is classified as _____________________.
Pylorus
Part of the stomach that secretes mucus
Body
Part of the stomach that secretes pepsin and HCl
Which is not a variable in the noyes and whitney equation
Ph
Following are some statements about phosphofluorescence
Phosphofluorescence is the energy released when triplet excited electrons return to the ground state Phosphofluorescence is a slower process and has a longer lifetime
Amber colored glass container is used to prevent the drug from
Photolysis
Thixotropy is a special characteristic that is exhibited by shear thinning systems, such as
Plastic and Pseudoplastic
1g of a drug s soluble in 10.50 L of water. Which one of the following correctly define its solubility as per USP definition
Practically insoluble
flocculation
Presence of vdW forces in some drug products causes agglomeration of flaky masses resulting from precipitation or coming out of a suspension or solution
A concept of the partition coefficient is involved in following areas of pharmaceutical sciences
Preservation of oil water systems Drug action in non-specific sites Absorption and distribution of drugs throughout the body
colligative
Properties that depend only on the number of ions or molecules and not the substance type
Select the correct order of degradation of a drug hydrolysis
Pseudo first order
the hydrolytic degradation of acetysalicylic acid in its aqueous suspension follows which kind of kinetic
Pseudo first order
Prout-Tompkins
Reaction kinetics in the solid state are modeled by this; the reaction rate is assumed to be proportional to the number of nuclei; includes an induction time required for generation of an appropriate density of active nuclei.
Gay-Lussac & Charles' law
Relates P, V, and T P1V1/T1=P2V2/T2
The amount of force per unit area that is applied to a liquid or semi solid is called
Shearing stress
Dissolution testing is conducted by manufacturers under what condition
Sink
Reservoir matrix
Soluble drug enclosed by insoluble membrane; water opens up pores through which drug is released; multi-unit systems are preferred to dec. risk of dose-dumping; modeled by Fick's 1st law and is 0-order bc of controlled membrane thickness
Recently, a compound pharmacist found out that he did not have methyl paraben; instead, he used butyl paraben and propyl paraben as preservatives for this emulsion. To his surprise, he found his emulsion showed some growth after a few days. Explain the possible cause of this problem, accounting for the antimicrobial mechanism of parabens.
Some of the parabens are more water soluble than others. As the chain length of the paraben increases, its aqueous solubility decreases and oil solu- bility increases. Due to the solubility and partition effects in the oil phase, and the interac- tion with emulsifiers, they may not attain an effective concentration in the aqueous phase. Since bacterial contamination happens in the aqueous phase, one may expect instability in the emulsion. In this case, both propyl and butyl parabens are more hydrophobic, and one expects more partition of both of these preserva- tives to the oil phase, causing even a further decrease of the effective antibacterial concentration in the aque- ous phase and causing an instability in this (o/w) emulsion.
1 gram of a drug is in 35 ml of water. which one of the following correctly define its solubility as per USP definition?
Sparingly soluble
Henry's law
States that the amount of gas that dissolves in a given type & volume of liquid is proportional to the partial pressure of a gas in equilibrium with the liquid.
HLB scale can be used to measure the following activity of a surfactant
Surface activity
Plastic flow is associated with
Suspensions
In a pressure cooker water boils at
Temp higher than 100C
Which of the following equations predicts the stability of a drug at room temp from experiments at accelerated condition at high temp
The Arrhenius Equation
Why do combination insulins behave differently than other insulin products?
The amorphous portion provides a quick release and absorption, followed by the slow release of the crystalline form
the term X in the freundich equation refers to
The amount of gas adsorbed
SFE
The best method for extracting essential oils from natural plant sources because: -highly selective for extracted compounds -allows extraction to occur at a lower T; reduces thermal degradation of extracted compound
Below are some potential applications of UV visible spectroscopy
The concentration of a protein solution can be calculated if its amino acid sequence and MW is known The presence of RNA as an impurity in a DNA sample can be determined by the ratio of its absorbance at 260nm and 280nm The extent of ionization of an acid can be easily determined
The Beer Lambert Law is the basis for deriving quantitive information from an absorption spectrum. Which of the following is the correct description of the constant in the mathematical equation representing the Beer Lambert Law
The constant K is called molar absorption coefficient if unit of concentration (c) is mole/liter The constant K is called specific absorption coefficient if unit of concentration (c) is gram/liter
nucleation
The critical step in initiation of crystal formation
Although NMR spectroscopy has intrinsically low sensitivity, it has many advantages as shown: The following are some of the potential applications of NMR spectroscopy:
The detection of decrease in phosphocholine level tumor cells The detection of decrease in urate oxidase level may indicate efficacy of antimicrobial agents against aspergillus nidulants The detection of decrease in urine hippurate and/or increase in plasma alanine level may indicate an increase in hepatic sensitivity
Intrinsic (dissolution rate)
The dissolution rate determination when surface area exposed to the solvent/medium remains the same
second, first
The hydrolysis of ethyl acetate is a _____-order reaction that is pseudo______- order in the case of a buffer medium
Molecularity
The number of molecules participating in a given step of a reaction and related to the mechanism of a reaction
Which one of the following is not affected by partition coefficient
The passage of water through biological membranes
The biological membrane is covered on both sides by lipid layers which are interrupted by water filled pores. Which statement is correct
The radius of the aqueous pores on biomembrane is approximately 4 angstrom, therefore any hydrophilic drug smaller than 4 angstrom can get transported through easily
When a drug is administered in a dosage form such as tablet, capsule, or suspension, the rate of absorption across the biological membrane frequently is controlled by
The slowest step involved in disintegration, dissolution, and absorption
How does temperature affect solubility
The solubility increase with higher temperatures for endothermic solids
There is evidence for the existence of diumal cycle of gastric acidity in humans. Which is correct in this regard
The stomach contents during nighttime are generally more acidic with approximate ph of 1.3
A higher frequency of occurrence of necrotizing enterocolitis (NEC) has been observed in premature infants in intensive care units fed enterally undiluted calcium lactate than those fed no calcium lactate or calcium lactate diluted with water or formula. Can you figure out why?
The tonicities of oral medications such as calcium lactate commonly used to feed premature infants kept in intensive care are very high, and this may lead to necrotizing enterocolitis if administered undiluted. The high osmolalities of orally fed nutritional supplements are the reason for the develop- ment of NEC in the premature infants
A 65-year-old HIV1 male patient is taking Atriplas (a combination of three medicines: efavirenz, tenofovir, and emtricitabine). A Foley catheter was inserted into his urinary bladder to help him pass urine. When he was also administered acyclovir (which has two pKas, 2.27 and 9.25), a white cloudy precipitate was observed in the catheter, indicating some sort of crystallization of acyclovir. This was further confirmed by the appearance of needle-like structures in the urine samples. What is your advice to this patient to overcome this problem of crystalluria?
The two pKas of acyclovir, an amphipathic drug, sug- gest its minimum solubility of 2.5 mg/mL at physio- logic pH. Generally, acyclovir intravenous infusion contains 50mg of acyclovir per mL. Therefore, to prevent formation of crystals in urine, both the infusion rate of acyclovir and the water intake should be manipulated. The former should be decreased, whereas the latter should be increased.
A patient suffering with osteoarthritis was administered a full course (one injection containing 20 mg of sodium hyaluronate in 2 mL phosphate buffered saline for 5 weeks) of Hyalgans (sodium hyaluronate injection) intra-articularly in the knee joint, but the symptoms did not improve significantly. What option or options would you suggest?
The viscoelasticity of sodium hyaluronate is mainly dependent on the molecular weight of hyaluro- nic acid used. The different brands of sodium hyaluro- nate vary in the molecular weight of hyaluronic acid used, Thus, the next logical viable option could be using Orthovisc or Euflexxa. Synvisc should be tried last because it consists of the highest-molecular-weight hya- luronic acid. you should note that although a high- er apparent viscosity is expected with an increasing molecular weight of hyaluronic acid, which could be expected to provide better cushioning and lubrication to joints, there could be limit because activity provided by hyaluronic acid is not only mechanical, but also could be biological.
Which one of the following statements is correct about diarrhea
There is a co-transport system unaffected by diarrhea causing microorganism, which transports Na+ ions to blood only when glucose is also present
Lineweaver-Burke
This equation is used to graphically obtain values of Km and Vmax for enzyme kinetics
Hixson-Crowell Cube Root Law
This law applies when the shape of the particles is uniform and does not change during dissolution
Sprowl's method
This method for adjusting tonicity uses "V" value which gives volumes in mL for 0.3 g of drug which the solution will be isotonic to which sufficient diluting isotonic solution can be added to obtain the desired volume.
The implantable Infusaid drug pump model 100 (Shiley Infusaid, Norwood, Mass.) is undergoing clinical trials as a drug delivery system in the treatment of osteomyelitis in your hospital. This study was evaluating the stability of vancomycin (1mg/ml) incubated at 37°C for 4 weeks in the pump. Both bioassay and high-pressure liquid chromatography data demonstrated a loss of at least 38% of activity over 4 weeks and colloidal precipitation of vancomycini in the pump at the end of the experiment. As the lead pharmacist in the team what will be your recommendation to the company and why?
This study demonstrated that vancomy- cin activity is reduced when the drug is incubated for 4 weeks at 37_C using a stability-indicating HPLC method. The drug also forms colloidal aggregates in the Infusaid drug pump model 100. Recommendations are not to use vancomycin in this drug pump. Future work that needs to be performed on vancomycin solu- tions, stability, and the drug pump should consider testing solutions with a pH of,3.0 or a solution pre- pared with some other diluent.
Which one of the following is the most desirable flow characteristic for a dosage form design
Thixotropic flow
Chemical with high Kd/w values are very hydrophobic
True
Cup and Bob type of viscometer may be used for gels and pastes
True
Different protons exist in different environments and thereby posses different magnetic strengrth
True
Digoxin is poorly soluble drug. Therefore, its physical forms such as particle size would have a significant effect on it therapeutic outcomes
True
Fluorescence spectroscopy could be many folds more sensitive than UV-visible spectroscopy
True
Generally, absorption or transport of a drug unionized form through gastrointestinal membrane would be more than its ionized form
True
Generally, greater the value of partition coefficient, the higher the lipid solubility of the solute
True
Strong bases which are those with pKa values between 5 and 11 show ph dependence absorption
True
Strong bases which are those with pka values between 5 and 11 show dependent absorption
True
The greater the acidity constant the stronger the acid would be
True
The lower the pKa value for an acid, the greater hydronium ion concentration it would produce on being added to water
True
The lower the pka value for an acid, the greater hydronium ion concentration it would produce on being added to water
True
The polar surface area is defined as the sum of the Van Der Waals surface areas for the polar atoms, oxygens, nitrogens, and attached hydrogen atoms
True
The smaller the polar surface area of a drug the greater would be its oral absorption as well as penetration through the brain
True
The tallest signal in a mass spectrum of substance is called the base peak
True
The temperature can exert greater influence on the solubility of a drug if it is a weak acidic base
True
The transport of weak basic drugs across gastrointestinal membrane is influenced by ph only if their pKa values are within the range of 5-7
True
Tyrosine and tryptophan are most prominent amino acids capable of producing fluorescence when exposed to radiation of wavelength 190nm
True
Viscosity is the reciprocal of fluidity
True
generally the greater the value fof partition coefficient the higher the lipid solubility of solute
True
the most commonly used method to measure lipophilicity is by determining partiriton coefficient using shake flask method
True
the rate of general acid and base catalysis is affected by concentration of undissociated buffer components in addition to hydronium and hydroxyl ion concentration
True
Experimental
Type of determination of reaction order in which data is obtained and substituted into rate equations to calculate k. A consistent k for each time point represents the reaction order.
Graphical
Type of determination of reaction order in which experimental data is plotted in the form of rate equations to determine the best fit
Isolation
Type of determination of reaction order in which the reaction is run in large XS of one reactant to determine the partial order and overall order of the reaction
cationic
Type of surfactant that has a cationic hydrophilic group; name will contain an anion (bromide, chloride, etc.)
anionic
Type of surfactant that has an anionic hydrophilic group; name will contain a cation (sodium, etc.)
HLB (hydrophilic-lipophilic balance) Scale
Used to measure the surface activity of surfactants
Fick's first law of diffusion
Used with high concentration gradient, describes the relationship between the amount of mass transfer occurring and the driving force responsible for the transfer
Following are some of the potential applications of mass spectroscopy
Useful in proving the identity of a compound and establishing its structure Provides an exact molecular weight and molecular formula of a substance
The arrhenius equation of rheology expresses the relationship between
Viscosity and temperature
Which of the following is correct? a. The diarrhea causing microorganisms impair either the cryptic or villus cells activity but never activity of both which results into more production of Cl ions or less absorption of nutrients and Na+ ions b. The intestinal villi cells absorb nutrients and Na+ ions from food and pump these ultimately into the circulatory system which creates the flow of water from the blood to intestine c. The net result of impairment of cryptic and villus cells activity is flow of water from intestinal lumen towards blood d. Water from blood flows into intestinal lumen due to secretion of Cl- ions into the intestinal lumen by cryptic cells
Water from blood flows into the intestinal lumen due to secretion of Cl- ions into the intestinal lumen by cryptic cells.
A typical IR spectrum can be broadly divided into two parts
Wave number range of 1450-600 cm is the fingerprint because unique for a specific substance Wave number range of 4000-1450 cm called the frequency region because unique for a specific functional group present in a substance
[S]
When [Substrate]<<Km the velocity of the rxn is directly proportional to ___________.
Vmax, independent
When [Substrate]>>Km the velocity of the rxn approaches ___________, and is ___________________ (dependent or independent) of substrate concentration
100mL of water was added to a 200mL solution. When the total volume was measured, it was found only 298mL even if there is no loss of material during mixing. Is this a real solution
Yes
The area under a peak NMR spectrum indicates the # of protons representative of that peak
Yes
T, d
____=10-____; conversion between tau and delta scales for NMR
Low
______ dielectric constant favors reactions between oppositely charged ions
High
______ dieletric constant favors reactions involved the formation of charged/polar transition states from neutral molecules
plasma, whole blood
_________ shows only viscosity, which ______________ (2wds) shows both viscosity and elasticity
An increase in temp by 10 deg. Celcius near room temperature is known to cause
a 2-4 fold increase in reaction rate for many reactions
136. The rate or speed of a process a physical or chemical change can be defined by a. The rate at which teh concentration of a species undergoing teh change decreases b. The rate at which the concentration of the resulting species increases with time c. The rate at which the concentration of the resulting species decreases with time
a and b
In a second order reaction a. Rate of reaction depends on concentration of two reacting species b. A plot of time (as abscissa) against (ao-a)/(aa0) (as ordinate) is linear with a slope equal to 1/k2 c. The half-life is independent of concentration d. The unit of k is concentration/time
a and b
Below are some statements about the relationship between pKa of a weak acidic drug and pH of gastrointestinal tract a. Weak acidic drugs are predominantly in the un ionized form at lower pH of the gastric fluid and therefore may be absorbed from stomach as well as form the upper part of the intestine b. Weak acidic drugs are predominantly in the ionized form at lower pH of the gastric fluid and therefore may be absorbed from the stomach as well as from the upper part of the intestine c. Some very weakly acidic drugs, such as phenytoin and many barbiturates, having pKa values greater than 8 would get absorbed quickly which is not dependent on pH
a and c
a. Phosphorescence is the energy released when triplet excited electrons return to ground state b. Phosphorescence is the energy released when singlet excited electrons return to the ground state c. Phosphorescence is a faster process and has a shorter lifetime than those of fluorescence d. Phosphorescence is a slower process and has a longer lifetime than those of fluorescence
a and c
h-bonding
a lone pair of electrons of an electronegative atom interact with an H bonded to another electronegative atom
a base catalyzed hydrolysis of an ester such as chloramphenicol palmitate can exhibit
a second-order kinetics only if the concentration of both - ester and base are changing, and a pseudo first-order kinetics if the concentration of the hydroxyl ion is maintained constant
prout tompkins model best describes
a solid state reaction
prout-tompkins model best describes
a solid state reaction
anisotropic
a type of solid with differing properties in all solid regions
isotropic
a type of solid with the same properties in all solid regions
which one of the following fact is/are correct with respect to thixotropy
a. Thixotropy is exhibited by shear thinning systems, such as pseudoplastic and plastic liquids b. Thixotropy can be defined as an isothermal and comparatively slow recover on standing of a material of a consistency lost through shearing c. Thixotropic behavior is useful for many pharmaceutical preparations suspensions d. Thixotropic system becomes more viscous upon application of shear
the key factors in the viscoelasticity of blood are
aggregation and deformability
The driving force for processes to occur is
all systems spontaneously move towards lower free energy and higher entropy
debye's forces
also called polarization, forces between uncharged polar and nonpolar molecules (dipole-induced dipole)
the equivalent temperature in Kelvin degree is
always bigger than Celius
under which situation will the viscosity of the oil increase
as temperature decreases
89. Which one of the following is not affected by partition coefficients a. Dissolution, absorption, distribution, metabolism, elimination, and protein binding of a drug b. The passage of water through biological membrane c. The relationship between molecular structure and biological activity of a drug d. The solubility and permeability of a drug
b
UV absorption spectroscopy can be used for detecting impurity in its substance. which one of the following is correct about the prescence of benzen as impurity in cyclophexane?
benzene absorbs 255nm while Cyclo absorbs 200nm
The key factor in the viscoelasticity of blood are
both aggregation and deformability
The duNouy tensionmeter can be used to measure
both surface and interfacial tension
erg
cgs energy units; 1 g*cm^2/s^2
dyne
cgs force units; 1 g*cm/s^2
in case of cyrstalline solids changes on the freezing or melting point with pressure may be calculated using
clapyeron equation
polymorphism
compounds in different crystalline structures
CMC (critical micellar concentration)
concentration above which the monomers of surfactant begin to form micelles
In a zero order reaction what is the unit of K0
concentration/time
the process by which a physically adsorbed gas is removed is called
desorption
The Lineweaver-Burke equation for an enzymatic reaction is useful for
determining the constant Km in Michaelis Menton equation and determining the constant Vmax in Michaelis Menton equation
Polymorphs are same substance but in different crystalline forms which are characterized by
different melting points, xray diffraction pattern, solubility
the release of a drug from matrix system occurs by
diffusion from the matrix system and erosion of the matrix system
systems which increase in volume when sheared are
dilatant
which one of the following is the most undesirable flow of characteristic for a dosage form design
dilatant flow
thixotropy is a special characteristic that is exhibited by shear thinning systems such as
dilatant, pseudoplastic
for newtonian fluids, if the rate of shear is increased two times from its original value while the viscosity remains constant. What change would you expect in shearing stress of that liquid
double of its original value
the force required to detach the ring from the surface/interface, in the Dunouy ring method is recorded in
dynes
splitting of a NMR peak occurs due to
effects of neighboring protons
a matter that exhibits plastic flow, below its yield value would behave as
elastic solid
triplet
electrons in an excited state positioned in a way such that their spins are parallel
singlet
electrons positioned in a way such that their spins are antiparallel to eachother, resulting in a 0 energy for the state; can be ground or excited state
sodium chloride and methane are
electrovalent anbd covalent compounds
allotropism
elements in different structures (diamond vs. graphite)
luminescence
emission of absorbed energy
46. Benzene is a colorless organic solvent but nitro benzene is pale yellow liquid while p hydroxynitrobenzene is a deep intense yellow liquid. This shift in appearances of color for these three subtances can be explained on the basis of concept of chromophore and auxochromes. Please select correct example of chromophore and auxochromes in the example of nitrobenzene and p hydroxynitrobenzene from the options shown below a. Benzene and hydroxyl group is an example of chromophore while Nitro group is of auxochrome b. Hydroxyl group is an example of chromophore while benzene and Nitro group is of auxochrome c. Hydroxyl group is an example of chromophore while Nitro group is of auxochrome d. Nitro group is an example of chromophore while hydroxyl group is of auxochrome
example of chromophore while hydroxyl groups is of auxochrome
A solution isomotic with blood would be definitely isotonic too
false
Adsorption is a bulk phenomena
false
It is conceivable for a reaction to have zero or fractional molecularity
false
The rate of specific acid and base catalysis is affected by concentration of undissociated buffer components in addition to hydronium and hydroxyl ion concentration
false
digestion and absorption of foodstuff occur separately at different times in the small intestine
false
for real gases the collision between particles is perfectly elastic
false
it is conceivable for a reaction to have fractional or zero molecularity
false
polymers in solution generally exhibit plastic flow
false
pseudoplastic flow has a yield value
false
the critical temperature and pressure for CO2 are 31C and 74.9 atm respectively. Can you liquefy Co2 stored at 100C by applying pressure
false
the higher the HLB value of an agent the more lipophilic it is
false
thioxotropy is a comparatively fast recovery of a material of a consistency lost due to shearing stress
false
osmolarity is expressed as osmol/kg of water
false`
fluorescence
fast; electrons returning to ground state emitting energy from excited singlet state
adhesive
forces between particles of different substances
cohesive
forces between particles of the same substance
Keesom's
forces between uncharged molecules with a dipole (dipole-dipole interaction)
chromophore
functional gp having its own characteristic uv-vis absorption; conjugation w these leads to a longer wavelength and an increase in absorptivity; examples include nitrile, nitro, nitrite, nitrate, azo, nitroso, ethene, thiol, and benzene
the statement in general the higher temperature the greater the solubility of a drug is applicable only for those solids which possess
higher positive heat of solution
Which of the following is not a characteristic of solid state reaction
homogenous medium
the surface and core of the micelles formed in an aqueous medium are
hydro and lipo philic
initial burst release is observed for which of the following matrix based controlled drug release system
hydrophilic or swellable matrix system
auxochrome
increase absorption of compounds to which theyre attached, do not have their own absorption bands; examples include hydroxyl, amino, aldehyde, methylmercaptan
dissolution rate can be increased by
increasing the diffusion coefficient
ion-dipole
interaction between and ion and a polar molecule
ion-induced dipole
interaction between ion and nonpolar molecule
The rate of dissolution when surface area exposed to the solvent/medium remains the same is called
intrinsic dissolution rate
the rate of dissolution when surface area exposed of the solvent medium remains the same is called
intrinsic dissolution rate
nonpolar
isobutanol and octanol are commonly used as this type of solvent
Which of the following is NOT a characteristic of solid state reaction?
it happens in a homogenous medium
stoke
kinematic viscosity units; 1 cm^2/s
amphoteric
lecithin is an example of a/an _______________ surfactant
the intermolecular distance in solid is
less than both liquid and gas
Ostwald viscometer is used for
liquids that flow relatively easily
Korsmeyer Peppas model
log (Mt/Minf)=logk+nlogt where values of n characterize drug release mechanisms of swellable (hydrophilic) matrix systems
A substance which is bound together by weak forces is said to have
low heat of fusion and melting point
cholesterol
maintains the rigidity and is the main barrier to permeability of water, glucose, ions, etc. in the biological membrane
capillary rise method
method of determining only surface tension
the number of moles of a solute per kilograms of the solvent is termed as
molality
the peak at highest m/z ration in a mass spectrum of a drug is indicative of
molecular weight of drug
small intestine
most absorption happens in this region of GI tract because of HUGE surface area
Super Case II (unknown)
n>1
We have a 1:1 mixture of a polar and non polar solvent. If we add a non polar drug to this mixture where would you find most of the drug?
non polar solvent
monotropic
only one polymorph is stable at all temperatures below melting point
Which is not a variable in the Noyes and Whitney equation
pH
Raoult's law
partial pressure exerted by by a solvent vapor above a solution equals a product of the mol fraction of the solution times the vapor pressure of a pure solvent
Amber colored glass container is used to prevent the drug from
photolysis
Hydrogen peroxide is stored in dark container to prevent it from
photolysis
Diffusion
process of mass transfer brought about by random (Brownian) particle motion; regulated by molecular weight/size of molecule
The hydrolytic degradation of acetylsalicylic acid in its aqueous suspension follows which kind of kinetic
pseudo zero-order
First-order
rate dependent on concentration A plot of the logarithm of concentration at any time vs time would be linear with slope = -k1/2.303 and the intercept on y-axis = log a0 half-life is independent of concentration units of k are 1/s
Second-order
rate dependent on concentration plot of t on abscissa vs ((a0-a)/(aa0 )) on ordinate would be linear which slope = k2 half-life is dependent on concentration units of k are L/mol*s
Zero-order
rate is independent of concentration Plot of x i.e the amount of drug degraded (as ordinate) against time (as abscissa) is linear with a slope = k0 half-life is dependent on concentration Plot of a i.e the amount of drug at any time "t" (as ordinate) against time (as abscissa) is linear with a slope = - k0 and intercept = a0 units of k are mol/L*s
Concentration dependencies
rate: IDD half-life: DID
Boyle's law
related pressure and volume PV=k
the amount of force per unit area that is applied to a liquid or semi solid is called
shearing stress
Dissolution testing is conducted by manufactures under what codnitions
sink
phosphorescence
slow; electrons returning to ground state emitting energy from excited triplet state
nonionic
spans, tweens, pluronic F127 are examples of _______________ surfactants
Dalton's law
states that the total pressure of a mixture of unreactive gases is the sum of all component partial pressure
Select the most appropriate term which completes this sentence: at the diffusion layer and displays a greater rate of dissolution under conditions of more acidic simulated gastric fluid than salicylic acid
supersaturation
Sodium salicylate is capable of _____ at the diffusion layer and displays a greater rate of dissolution under conditions of more acidic simulated gastric fluid than salicylic acid
supersaturation
plastic flow is associated with
suspensions
Flux
the amount of material moving across unit cross-sectional area of a barrier per unit time
Which of the following equations predicts the stability of a drug at room temperature from experiments at accelerated condition at higher temperature
the arrherius equation
the temperature at which the vapor pressure of a liquid equals the external atmospheric pressure is known as
the boiling point
which is correct? a. The diarrhea causing microorganisms impair either the cryptic or villus cells activity or activity of both which results into more production of Cl- ions or less absorption of nutrients and Na+ ions b. There is a co- transport system unaffected by diarrhea causing microorganism, which transports Na+ ions to blood regardless of the presence of glucose c. There is no co transport system for other substances except glucose and sodium ions in intestine d. The net result of impairment of cryptic and villus cells activity is flow of water from intestinal lumen towards blood
the diarrhea causing microorganism impair either the cryptic or villus cells activity or activity of both which results into more production of Cl- ions or less absorption of nutrients and Na+ ions.
solubility
the most important macroscopic property in pharmacy
A 20% salicylic acid ointment was prepared for a patient to use as a wart treatment. After one week of treatment, the patient did not see a keratolytic effect of this particular batch of ointment. The patient reported this failure to the pharmacist who compounded the prescription. How should the pharmacist respond to this situation?
the pharmacist should get an IR spectrum of the salicylic acid used in the preparation. This IR spectrum should be compared to the library data that already exists for salicylic acid. If the spectra are differ- ent, then the salicylic acid used in the preparation is not really salicylic acid.
solubilization
the process of increasing aqueous solubility of a drug thru presence of surfactant at or above CMC
The rate or speed of a process can be defined by
the rate at which the concentration of a species undergoing the change decreases, and the rate at which the concentration of the resulting species increase with time
In a zero order reaction
the rate of decomposition is independent on the concentration of any of the reactants
The plasma level of an orally administered tablet depends on
the rate of tablet disintegration and the rate of dissolution of the drug
Hixson-Crowell Cube Root Law is capable of determining dissolution rate when
the shape of the dissolving particle is uniform and does not change during dissolution
Solute was added to a solvent and mixed well. some of the solute settled to the bottom of the container. which statment best explains why all the solute did not dissolve
the solution had become saturated
In a study of the hydrolysis of a drug in aqueous solution a plot of logarithm of the amount of the drug remaining (as ordinate) against time (abscissa) is linear
the unit of k is concentration-1time-1
which one of the following is the most desirable flow characteristic for a dosage form
thixotropic
solvate
trapped solvent during crystallization results in a solid called a _________________
Chromatography is an application of adsorption by solids
true
Cup and bob type of viscometer may be used for gel and pastes
true
Digosin is a poorly soluble drug. therefore its physical forms such as particle size would have a significant effect on its therapeutic outcomes
true
For a single step (elementary) reaction, the molecularity and order are the same
true
Fora single step elementary reaction the molecularity and order are the same
true
Generally, surface area does not remain constant throughout the dissolution process
true
Insoluble ploymers such as ethyl cellulose, methyl methacrylyate or polyvinyl acetate are used for making inert matrix based extended drug released system
true
Insoluble polymers such as ethyl cellulose, methylmethacrylate, or polyvinvyl acetate are used for making inert matrix-based extended drug release systems
true
It is not conceivable for a reaction to have zero or fractional molecularity
true
Surface area does not remain constant throughout the dissolution process
true
The greater the the acidity constant Ka the stronger the acid would be
true
Transport of weak acidic drugs across GU membrane is influenced by pH only if their pka values are within the range of 3-7
true
When a liquid is placed in an evacuated container ( container that has a vaccum above the liquid surface) at a constant temeprature, some molecules with the highest energies break away from the surface of the liquid and pass into the vapor state and some of the molecules subsequently return to the liquid state or condense.
true
below the critical micelle concentration surface properties are affected
true
generally branched chain is more soluble than straight chain of an isomer
true
osmolarity is expressed as osmol/L of aqueous solution
true
temperature can exert greater influence on the solubility of a drug if it is a weak acid or base
true
the glass transition temperature for an amorphous solid is a the mid-point of the transition in which the solid converts from a glassy to rubber state
true
the high tonicity of calcium lactate administered in premature baby in intensive care units may lead to necrotizing eneterocolitis
true
the polar surface area is defined as the sum of the VDW surface areas for the polar atoms oxygen nitrogens and attached hydrogen atoms
true
the rate of general acid and base catalysis is affected by concentration of undissociated buffer components in addition to hydronium and hydroxyl ion concentration
true
viscosity is the reciprocal of fluidity
true
enantiotropic
two polymorphs with two different stable temperature ranges
physical
type of adsorption between solid and gas that is due to VdW forces and is reversible
chemical
type of adsorption between solid and gas that is due to chemical bonds and is irreversible
Dilatant
type of flow; increase in shearing stress caused an increase in resistance to flow; exhibited by suspension > 50% w/v
plastic flow
type of flow; material will not flow until shearing stress exceeds yield value; above YV behaves as a Newtonian liquid, below YV behaves as an elastic solid; exhibited by concentration suspension
Pseudoplastic
type of flow; will flow more readily with increase in shearing stress; exhibited by polymers in soln
dunouy ring method
used to determine either interfacial or surface tension; measures F required to detach Pt-Ir ring at surface or interface
Following are some approaches to prevent the oxidative degradation of drug
using an initiation inhibitor such as EDTA, using colored glass containers, using chain breakers such as alpha tocopherol, using oxygen scavengers such as sodium metabisulfite and ascorbic acid
C-C equation for liquids establishes relationships between
vapor pressure and absolute temperature
poise
visocity units; 1 g/(cm*s)
the attractive forces between molecules are called adhesive forces?
water and air
ampicillin degrades much faster in water than in alcohol because
water, being a high dielectric constant solvent, converts the neutral ampicillin into a charged transition complex
Which of the following are not correct according to the ph partition hypothesis of drug absorption
weak basic/ neutral drugs may be absorbed from the stomach bust basic drugs are not
Indicate which is correct? a. A solution that has a greater osmotic pressure than plasma is said to be hypotonic b. When red blood cells are immersed in a hypotonic solution they will shrink c. The chemical potential or concentration of solvent molecule in the solution is greater than that in pure solvent d. When a solution is contained within a semipermeable membrane and separated from the solvent, the solvent will pass across the membrane into the solution
when a solution is contained within a semipermeable membrane and separated from the solvent, the solvent will pass across the membrane into the solution
Which is correct? a. When a solution is contained within a semipermeable membrane and separated from the solvent, the solvent will not pass across the membrane into the solution b. A solution that has a greater osmotic pressure than plasma is said to be hypotonic c. The chemical potential or concentration of solvent molecule in the solution is greater than that in pure solvent d. When red blood cells are immersed in a hypotonic solution they will swell
when red blood cells are immersed in a hypotonic solution they will swell
hydrate
when the solvent trapped in the solid during crystallization is water, the resulting solid is called a __________________