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WorksheetsCeutics Exam 2 - Dissolution Jambhekar
Total questions: 85
Worksheet time: 43mins
Name
Class
Date
1.
What is osmosis
a)
solvent molecules move from low concentration to high concentration
b)
solvent molecules move from high concentration to low concentration
c)
solute molecules move from high concentration to low concentration
d)
solute molecules move from low concentration to high concentration
2.
What is diffusion
a)
solvent molecules move from low concentration to high concentration
b)
solvent molecules move from high concentration to low concentration
c)
solute molecules move from high concentration to low concentration
d)
solute molecules move from low concentration to high concentration
3.
Diffusion is the result of random molecular motion due to thermal agitation
a)
true
b)
false
4.
Molecules that migrate from one location to another location are called
a)
diffusants
b)
permeants
c)
penetrants
d)
solutes
5.
What is the medium in which the diffusants migrate
a)
diffusional barrier
b)
permeants
c)
penetrants
d)
concentration gradient
6.
What is a concentration gradient
a)
the concentration profile of the diffusant in the diffusional barrier
b)
concentration difference at different locations within the barrier
c)
driving force for diffusion of molecules from region of high concentration to low concentration
d)
driving force for diffusion to go from regions of low concentration to high concentration
7.
Which equation is Fick's First Law of Diffusion
a)
J = -D (dC/dX)
b)
D = (RT/Nf)
c)
PV = nRT
d)
D = KT/f
8.
In Fick's First Law of Diffusion, J = -D(dC/dX), what does J stand for and what is the units
a)
flux
b)
diffusion coefficient
c)
amount[mg]/(cm^2*min)
d)
cm^2/min
e)
concentration gradient
9.
In Fick's First Law of Diffusion, J = -D(dC/dX), what does D stand for and what is the units
a)
flux
b)
diffusion coefficient
c)
amount/(cm^2*min)
d)
cm^2/min
e)
concentration gradient
10.
In Fick's First Law of Diffusion, J = -D(dC/dX), what does dC/dX stand for and what is the units
a)
flux
b)
concentration gradient in the direction of X
c)
amount/(cm^2*min)
d)
mg/(cm^3*cm)
e)
diffusion coefficient
11.
In Fick's First Law of Diffusion, J = -D(dC/dX), the negative sign indicates that
a)
the molecular movement in the direction of lower concentration
b)
the molecular movement in the direction of higher concentration<br />
12.
Under defined conditions, the diffusion coefficient is constant
a)
true
b)
false
13.
What is flux (J)
a)
the measure of the rate (speed or velocity) of molecular diffusion through the diffusional barrier
b)
the amount (mg or g) of solute crossing a plane of unit surface area (cm^2) per unit time (sec, min, hr)<br />
c)
distance (cm^2) traveled by the solute per unit time<br />
d)
change in concentration over the small distance
14.
What is diffusion coefficient (D)
a)
the measure of the rate (speed or velocity) of molecular diffusion through the diffusional barrier
b)
the amount (mg or g) of solute crossing a plane of unit surface area (cm^2) per unit time (sec, min, hr)<br />
c)
distance (cm^2) traveled by the solute per unit time<br />
d)
change in concentration over the small distance
15.
What is dC/dX
a)
the measure of the rate (speed or velocity) of molecular diffusion through the diffusional barrier
b)
the amount (mg or g) of solute crossing a plane of unit surface area (cm^2) per unit time (sec, min, hr)<br />
c)
distance (cm^2) traveled by the solute per unit time<br />
d)
change in concentration over the small distance
16.
What is the equation for diffusion coefficient (D)
a)
J = -D (dC/dX)
b)
D = (RT/Nf)
c)
PV = nRT
d)
D = KT/f
17.
In the Diffusion Coefficient equation, D = RT/Nf, what is R
a)
gas constant
b)
absolute temperature
c)
Avogadro's number
d)
frictional coefficient
18.
In the Diffusion Coefficient equation, D = RT/Nf, what is T
a)
gas constant
b)
absolute temperature
c)
Avogadro's number
d)
frictional coefficient
19.
In the Diffusion Coefficient equation, D = RT/Nf, what is N
a)
gas constant
b)
absolute temperature
c)
Avogadro's number
d)
frictional coefficient
20.
In the Diffusion Coefficient equation, D = RT/Nf, what is f
a)
gas constant
b)
absolute temperature
c)
Avogadro's number
d)
frictional coefficient
21.
What is another equation for diffusion coefficient that uses Boltzmann's constant
a)
J = -D (dC/dX)
b)
D = (RT/Nf)
c)
PV = nRT
d)
D = KT/f
22.
Based on the diffusion coefficient equation that uses Boltzmann's constant (K), D = KT/f, what is the diffusion coefficient influcenced by
a)
temperature
b)
pressure
c)
solvent properties
d)
chemical nature of the diffusant
23.
For dilute systems containing spherical particles, what is the Sutherland-Einstein diffusion coefficient equation
a)
J = -D (dC/dX)
b)
D = (RT/Nf)
c)
D = RT / 6πƞrN
d)
D = KT/f
24.
In the Sutherland-Einstein equation, D = RT / 6πƞrN, what is ƞ (eta) and its units
a)
coefficient of viscoity
b)
poise (dyne*sec/cm^2)
c)
radius of particle
d)
mm or mcg
25.
In the Sutherland-Einstein equation, D = RT / 6πƞrN, what is r and its units
a)
coefficient of viscoity
b)
poise (dyne*sec/cm^2)
c)
radius of particle
d)
mm or mcg
26.
What is the equation that shows the diffusion coefficient is inversely proportional to the molecular weight for spherical particles
a)
J = -D (dC/dX)
b)
D = (RT/Nf)
c)
D = RT / 6πƞrN
d)
D = KT/f
e)
D*⍺(molec weight)^-1/3
27.
Fick's first law of diffusion clearly indicates that the flux (J) is proportional to the ___ and ___
a)
concentration gradient
b)
diffusion coefficient
c)
pressure
d)
temperature<br />
e)
Avogadro's number
28.
The higher the concentration gradient in diffusion, the ___ the flux value<br />
a)
greater
b)
smaller
29.
The smaller the concentration gradient becomes over time in diffusion, the ___ the flux value<br />
a)
greater
b)
smaller
30.
In biological systems, Fick's First Law of Diffusion explains the passive diffusion involved in transfering drug molecules from the region of high concentration to the region of low concentration
a)
true
b)
false
31.
In Fick's First Law of Diffusion for a biological system, dC/dT can be written as
a)
K(Cgit - Cblood)
b)
(Km/fAD) / h
c)
KT/f
32.
In Fick's First Law of Diffusion for a biological system, what is the equation for the Specific Permeability Coefficient (K)
a)
K(Cgit - Cblood)
b)
(Km/f)AD / h
c)
KT/f
33.
In Fick's First Law of Diffusion for a biological system, K(Cgit - Cblood) where K = (Km/f)AD/h, what does A stand for and what are its units
a)
surface area
b)
diffusion coefficient
c)
partition coefficient of a drug between the membrane and aq fluid
d)
cm^2
e)
cm^2/min
34.
In Fick's First Law of Diffusion for a biological system, K(Cgit - Cblood) where K = (Km/f)AD/h, what does D stand for and what are its units
a)
surface area
b)
diffusion coefficient
c)
partition coefficient of a drug between the membrane and aq fluid
d)
cm^2
e)
cm^2/min
35.
In Fick's First Law of Diffusion for a biological system, K(Cgit - Cblood) where K = (Km/f)AD/h, what does Km/f stand for and what are its units
a)
no unit
b)
drug concentration
c)
partition coefficient of a drug between the membrane and aq fluid
d)
mcg/mL
e)
thickness of membrane<br />
36.
In Fick's First Law of Diffusion for a biological system, K(Cgit - Cblood) where K = (Km/f)AD/h, what does h stand for and what are its units
a)
cm
b)
drug concentration
c)
partition coefficient of a drug between the membrane and aq fluid
d)
mcg/mL
e)
thickness of membrane<br />
37.
In Fick's First Law of Diffusion for a biological system, K(Cgit - Cblood) where K = (Km/f)AD/h, what does Cgit stand for and what are its units
a)
cm
b)
drug concentration in gastrointestinal tract
c)
partition coefficient of a drug between the membrane and aq fluid
d)
mcg/mL
e)
drug concentration in blood<br />
38.
In Fick's First Law of Diffusion for a biological system, K(Cgit - Cblood) where K = (Km/f)AD/h, what does Cblood stand for and what are its units
a)
cm
b)
drug concentration in gastrointestinal tract
c)
partition coefficient of a drug between the membrane and aq fluid
d)
mcg/mL
e)
drug concentration in blood<br />
39.
Fick's law of diffusion states that the rate of absorption (dC/dt) is directly porportional to
a)
the surface area of the membrane
b)
the partition coefficient (Km/f) of a drug
c)
the diffusion coefficient (D) of the drug<br />
d)
the membrane thickness (h)
40.
Fick's law of diffusion states that the rate of absorption (dC/dt) is inversely porportional to
a)
the surface area of the membrane
b)
the partition coefficient (Km/f) of a drug
c)
the diffusion coefficient (D) of the drug<br />
d)
the membrane thickness (h)
41.
According to the pH partition theory of drug absorption, what often dictates the magnitude of the absorption of a drug following its availability in solution
a)
dissociation constant of a drug (pKa)
b)
lipid solubility of a drug (partition coefficient)
c)
pH of the fluid at absorption site
42.
The pH partition theory of drug absorption is based on what assumptions
a)
drugs are absorbed by passive transfer or diffusion
b)
drugs are preferentially absorbed in an unionized form
c)
drugs are sufficiently lipid soluble
d)
drugs are preferentially absorbed in an ionized form
43.
Most weak acids are predominantly present in the ___ form at low pH of gastric fluid
a)
unionized
b)
ionized
44.
What factors are not considered by the pH partition theory when discussing unfavorable ratios of unionized to ionized drug molecules in the small intesting
a)
long residence time
b)
limited absorption of ionized species
c)
large surface area
45.
Most weak basic drugs are ___ absorbed in the stomach since they remain largely ____ form at low pH
a)
poorly, ionized
b)
poorly, unionized
c)
well, ionized
d)
well, unionized
46.
Where does the majority of absorption take place for a weak basic drug and why
a)
stomach
b)
small intestine
c)
lipid solubility
d)
unionized form
e)
ionized form
47.
Most drugs, regardless of pKa, are absorbed in the
a)
stomach
b)
small intestine
c)
kidneys
d)
esophagus
48.
What is the oral bioavailability of a drug influenced by
a)
dissolution rate
b)
equilibrium solubility
c)
instestingal permeability
d)
pre-systemic metabolism
49.
Approximately 40% of the compounds that enter the development phase of drug development don't make it to the market due to
a)
cost
b)
biopharmaceutical properties
c)
drive
d)
manufacturing facilities
50.
What makes up the Biopharmaceutical Classification System (BCS)
a)
equilibrium solubility
b)
partition coefficient
c)
permeability of a drug
d)
dissolution of a drug
51.
What is the process by which solid particles dissolves in the surrounding liquid to form a clear solution
a)
equilibrium solubility
b)
partition coefficient
c)
permeability of a drug
d)
dissolution of a drug
52.
What is often the rate limiting step of drug absorption from the GI tract
a)
drug release
b)
partition coefficient
c)
permeability of a drug
d)
dissolution of a drug
53.
When a drug is administered orally in a solid dosage form, what is the first step before absorption can occur
a)
dissolution
b)
suspension
c)
GI absorption
54.
How was the Noyes-Whitney Equation of drug dissolution developed
a)
careful observation of dissolution behavior of solids in a solvent system
b)
careful experiments of dissolution behavior of solids in a solvent system
c)
careful observation of dissolution behavior of liquids in a solvent system
d)
careful experiments of dissolution behavior of liquids in a solvent system
55.
What is the Noyes-Whitney equation of drug dissolution
a)
dC/dt = (KDS/H)(Cs-C)
b)
D = (RT/Nf)
c)
D = RT / 6πƞrN
d)
D = KT/f
56.
In the Noyes-Whitney equation of drug dissolution, dC/dt = (KDS/H)(Cs-C), what is dC/dt
a)
rate of concentration change/dissolution rate
b)
dissolution rate constant
c)
diffusion coefficient<br />
d)
thickness of diffusion layer
e)
surface area of solid/crystal
57.
In the Noyes-Whitney equation of drug dissolution, dC/dt = (KDS/H)(Cs-C), what is K
a)
rate of concentration change/dissolution rate
b)
dissolution rate constant
c)
diffusion coefficient<br />
d)
thickness of diffusion layer
e)
surface area of solid/crystal
58.
In the Noyes-Whitney equation of drug dissolution, dC/dt = (KDS/H)(Cs-C), what is D
a)
rate of concentration change/dissolution rate
b)
dissolution rate constant
c)
diffusion coefficient<br />
d)
thickness of diffusion layer
e)
surface area of solid/crystal
59.
In the Noyes-Whitney equation of drug dissolution, dC/dt = (KDS/H)(Cs-C), what is h
a)
rate of concentration change/dissolution rate
b)
dissolution rate constant
c)
diffusion coefficient<br />
d)
thickness of diffusion layer
e)
surface area of solid/crystal
60.
In the Noyes-Whitney equation of drug dissolution, dC/dt = (KDS/H)(Cs-C), what is S
a)
rate of concentration change/dissolution rate
b)
dissolution rate constant
c)
diffusion coefficient<br />
d)
thickness of diffusion layer
e)
surface area of solid/crystal
61.
In the Noyes-Whitney equation of drug dissolution, dC/dt = (KDS/H)(Cs-C), what is Cs
a)
solubility of a drug in the solvent
b)
concentration of drug in the GI fluid
c)
concentration gradient
d)
thickness of diffusion layer
e)
surface area of solid/crystal
62.
In the Noyes-Whitney equation of drug dissolution, dC/dt = (KDS/H)(Cs-C), what is C
a)
solubility of a drug in the solvent
b)
concentration of drug in the GI fluid
c)
concentration gradient
d)
thickness of diffusion layer
e)
surface area of solid/crystal
63.
In the Noyes-Whitney equation of drug dissolution, dC/dt = (KDS/H)(Cs-C), what is (Cs-C)
a)
solubility of a drug in the solvent
b)
concentration of drug in the GI fluid
c)
concentration gradient
d)
thickness of diffusion layer
e)
surface area of solid/crystal
64.
What is another way to write the Noyes-Whitney equation of drug dissolution if you were provided the specific dissolution rate constant
a)
dC/dt = (KDS/H)(Cs-C)
b)
dC/dt = K1*S(Cs-C)
c)
D = RT / 6πƞrN
d)
D = KT/f
65.
What is the equation to find the specific dissolution rate constant
a)
dC/dt = (KDS/H)(Cs-C)
b)
dC/dt = K1*S(Cs-C)
c)
K1 = KD/h
d)
D = KT/f
66.
The specific dissolution rate constant (K1) is a constant for a specific set of conditions, though it is dependent upon<br />
a)
temperature
b)
viscosity of the fluid
c)
agitation of the fluids
d)
density of fluid
e)
volume of the liquid
67.
The Noyes-Whitney equation tells us that the dissoution rate (dC/dt) of a drug in the GI tract depends on
a)
diffusion coefficient (D) of a drug
b)
surface area (S) of the undissolved solid drug
c)
saturation or equilibrium solubility (Cs) of the drug in the GI tract<br />
d)
thickness of diffusion layer (h)
68.
According to the Noyes-Whitney equation, it is suggested that there are two main variables that govern the dissolution of a drug in the GI tract
a)
surface area (S) of a solid drug
b)
saturation or equilibrium solubility (Cs) of a drug in the GI fluid
c)
diffusion coefficient (D)<br />
d)
thickness of diffusion layer (h)
69.
The surface area (S) of the powder can be controlled by controlling the particle size of a drug
a)
true
b)
false
70.
The equilibrium solubility (Cs) of a drug can be controlled by
a)
proper selection of soluble salts - less soluble free acid or base form
b)
selecting amorphous or cystalline forms
c)
appropriate polymorph
d)
anhydrous or hydrous forms/modifications in a chemical structure
71.
There are many possible manipulations of physical-chemical properties of a drug to yield a better dissolution. Which manipulation has been the most thoroughly investigated
a)
reduction of particle size
b)
increasing particle size
c)
reduction of solubility
d)
increasing solubiity
72.
Generally, the smaller the particle size
a)
the larger the surface area
b)
the larger the specific surface
c)
the smaller the surface area<br />
d)
the smaller the specific surface
73.
A drug dissolves more rapidly when its surface area or specific surface is decreased
a)
true
b)
false
74.
Increasing surface area of a drug means reducing the particle size of the drug
a)
true
b)
false
75.
What can be done to formulations of tablets, capsules, and suspensions when a therapeutic agent is very hydrophobic to improve its dissolution rate
a)
adding a wetting agent
b)
reducing particle size
76.
How does a surface active agent facilitate the "wetting" of a powder
a)
lower interfacial tension between powder particle and surrounding liquid
b)
increase interfacial tension between the powder and surrounding liquid
c)
lower the contact angle
d)
increase the contact angle
77.
What are some commonly used wetting agents
a)
tween
b)
spans
c)
sodium lauryl sulfate sodium docusate
78.
How are solid dispersions prepared
a)
dissolving drug and carrier in suitable solvent
b)
solidfying mixture by cooling or evaporating
c)
reducing particle size
79.
How do you increase the solubility of a weak acid in the stomach to increase pH and transform the drug into its ionized form
a)
use a highly water-soluble salt of a weak acid
b)
mix or combine a basic substance in a formulation
c)
increase the pH of GI content by using antacids
80.
What are amorphous solids
a)
non crystalline powder
b)
crystalline powder
c)
anhydrous powder
d)
there is no definite order or extended crystal structure
e)
there is a definite order and crystal structure<br />
81.
What are amorphous solids also referred to as and why
a)
super-cooled liquids
b)
super-heated liquids
c)
random order of arrangement and distortion of shape under pressure
d)
organized order of arrangement and shape under pressure
82.
Amorphous materials have a definite melting point as the transition to a liquid state will occur over several degrees
a)
true
b)
false
83.
What are some characteristics of an amorphous form of a drug
a)
lacks a good hard crystal structure
b)
lacks strong forces
c)
more soluble and bioavailable than the crystalline solid form
d)
has a good hard crystal structure
e)
less soluble and bioavailable than crystalline solid form
84.
Amorphous forms tend to be usually of ____ thermodynamic energy than the corresponding crystalline form
a)
higher
b)
lower
c)
equal
85.
Upon storage, amorphous solids tend to revert to more stable form (not desired form)
a)
true
b)
false
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