Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Drug Delivery II > Exam 2 Dissolution > Flashcards

Exam 2 Dissolution Flashcards

1
Q

T or F: Dissolution is defined as the process by which a solid is transformed from aggregates of molecules or ions into a dissolved state (i.e. enters into solution)

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The rate of solution is determined by the rate of _______ of the dissolved substance through a thin layer that forms instantaneously around the solid particles

A

Diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

T or F: In the late 1960s, dissolution testing of solid dosage forms became a mandatory requirement for several drugs

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

T or F: The dissolution test is a simple and inexpensive measure of the physical consistency of the dosage form being evaluated

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In case of variation in dissolution results, one must investigate the causative sources, which are _________, ________, or ________

A

Raw material, formulation, or process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

T or F: Dissolution is the process by which a solid substance dissolves

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Dissolution is controlled by the ______ between the solid substance and the solvent

A

Affinity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Factors that influence the dissolution rate

A
  • Physical characteristics of the dosage form
  • Wettability of dosage unit
  • Ability of the dissolution medium to penetrate the dosage form
  • Swelling process
  • Disintegration and deaggregation of dosage form
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The speed of wetting is dependent on the _______ ______ between the solid surface and dissolution medium

A

interfacial tension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Hydrophobic lubricants such as ____ and ______ ______ slow the penetration rate of the medium; thus slowing the __________ of the granules

A

talc, magnesium stearate; deaggregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Absorption rate-limiting step for freely-soluble drugs

A

Diffusion across the GI membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Absorption rate limiting step for poorly-soluble drugs

A

Dissolution of the drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Physical parameters that control the rate at which a substance dissolves

A
  • Surface area at a given time
  • Shape of the particles
  • Nature of the solid/liquid interface
  • Solubility of the solid in the dissolution medium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Mathematic equation of the rate of dissoltion

A 
dM/dt = KA (Cs - C)
M = mass of the substance dissolved during time t
A = area exposed to the dissolution medium
Cs = solubility of the drug
C = concentration of drug in solution at time t
K = intrinsic dissolution rate constant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

dM/dt = KACs is known as what equation?

A

Sink-condition equation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The intrinsic rate of dissolution is determined by using either the ____ disk system, or the ____ disk system

A

rotating; stationary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Flux equation

A

J = (dM/dt) * (1/A)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Factors related to the physiochemical properties of the drug (2)

A
  • Solubility

- Particle Size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The major factor that determines the rate of dissolution and can be used as a rough predictor of bioavailability

A

Solubility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

T or F: Increasing the particle size results into larger surface area, and subsequently faster dissolution

A

False: Decreasing the particle size increases surface area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The surface area accessible by the medium is known as

A

Effective surface area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

T or F: It is assumed that the solubility of the drug is dependent on particle size

A

False: solubility is independent of particle size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

T or F: Extreme reduction in particle size can lead to an increase in solubility

A

True

24
Q

T or F: Amorphous form of a drug exhibits greater solubility and faster dissolution rate than the crystalline form

A

True

25
Q

Factors related to drug product formation (4)

A
  • Effects of diluents
  • Effects of granulating agents
  • Effects of disintegrates
  • Effects of lubricants
26
Q

T or F: The use of hydrophilic diluents such as starch, lactose, microcrystalline cellulose (insoluble) tends to increase the hydrophilicity of poorly soluble active ingredients and result in improvement of dissolution rate

A

True

27
Q

Which diluent, lactose or calcium carbonate, in warfarin tablets, will result in a greater increase in prothrombin time?

A

(look up)

28
Q

T or F: Hydrophobic lubricants such as magnesium stearate, aluminum stearate, stearic acid, and talc reduce the wettability of tablets, resulting in longer disintegration time, and smaller area of contact between the active ingredient and dissolution medium

A

True

29
Q

Factors related to the processes used in the manufacture of the product (2)

A
  • Effect of method of granulation

- Effect of compression force

30
Q

Which granulation method is considered superior with respect to enhancing the dissolution characteristics of tablets

A

Wet granulation

31
Q

What are five characteristics of compressed tablets that are influenced by the compression force during tableting?

A
  1. Apparent density
  2. Porosity
  3. Hardness
  4. Disintegration time
  5. Average primary particle size
32
Q

Factors related to dosage form (2)

A
  • Effect of deaggregation

- Effect of drug-excipient interaction

33
Q

Factors related to the dissolution test

A
  • Agitation intensity
  • Temperature
  • Effect of pH
  • Effect of surface tension
  • Effect of viscosity
34
Q

T or F: The degree of agitation, or stirring conditions, influences the diffusion-controlled dissolution markedly due to its effect on the diffusion layer

A

True

35
Q

T or F: Thickness of the diffusion layer is directly proportional to agitation speed

A

False; it is inversely proportional

36
Q

T or F: Purified water is usually used as the dissolution medium unless investigations show a specific need for an acidic solution

A

True

37
Q

T or F: Surfactant acting as wetting agents lowers the contact angle and thus improve penetration of the dissolution medium, which leads to an enhancement in dissolution rate

A

True

38
Q

T or F: The dissolution rate of benzoic acid was found to be inversely proportional to the viscosity of the medium

A

True

39
Q

USP Method 1 is known as what method of Dissolution?

A

Rotating basket method

40
Q

USP Method 1 has a stainless steel ____-mesh wire basket that rotates at speeds of ___-___rpm. Temperature is maintained around ___ degrees celsius, and the assembly should not be exposed to significant motion, agitation or vibration. The dosage is placed in the basket at the ____ (start/middle/end) of the test, and is immersed in usually ____mL of dissolution medium

A 
40-mesh
25-150rpm
37 degrees C
start of test
900 mL
41
Q

USP Method 2 is known as what method of dissolution?

A

Rotating paddle method

42
Q

In USP Method 2, a _____ is substituted for a basket, and the dosage form is allowed to ____ (float/sink) before the paddle is activated. The apparatus frequently used for both disintegration and nondisintegrating dosage forms at ___rpm.

A

paddle
sink
50rpm

43
Q

For floating dosage forms, a ____ of non-reactive material is used as a “sinker” to keep the unit at the bottom of the vessel.

A

helix

44
Q

In case of a nondisintegrating dosage form, Apparatus ___(1 or 2) is preferred since the dosage form is kept constrained in steady state fluid flow

A

Apparatus 1 (basket)

45
Q

USP Method 3 is known as what method of dissolution?

A

Reciprocating cylinder

46
Q

The assembly of USP Method 3 consists of a set of ____ (metal/glass) reciprocating cylinders fitted with screens on the top and bottom. A ____ and ____ assembly to reciprocate the cylinders ______ (horizontally/vertically) inside their vessels. The GI tract conditions can easily be simulated by making time dependent ___ changes.

A

Glass
motor and drive
vertically
pH changes

47
Q

USP Method 3 is most suitable for _________ or ______ _____ dosage forms

A

Nondisintegrating (Extended release)

Delayed-release (enteric coated)

48
Q

USP Method 4 is known as what method of dissolution

A

Flow-through cell

49
Q

In USP Method 4, a ____ forces the dissolution medium upwards through the flow-through cell at a certain flow rate. The flow profile is sinusoidal with ___ +/- ____ pulses/minute

A

Pump

120 +/- 10

50
Q

USP Method 5 is known as what method of dissolution?

A

Paddle over disk

51
Q

In USP Method 5, apparatus ___ (1, 2, 3, or 4) is used, and a stainless steel disk assembly for holding a ______ _____ is placed at the bottom of the vessel. Temperature is maintained at ____ +/- ___ degrees C

A

Apparatus 2
Transdermal Patch
32 +/- 0.5 degrees C

52
Q

USP Method 6 is known as what method of dissolution?

A

Cylinder

53
Q

In USP Method 6, the assembly is the same as apparatus ____ (1, 2, 3, or 4), except the _____ is replaced by a cylinder. The _____ _____ is attached to the cylinder, and temperature is maintained at ____ +/- ____ degrees C

A

Apparatus 1
Basket
Transdermal Patch
32 +/- 0.5 degrees C

54
Q

USP Method 7 is known as what method of dissolution?

A

Reciprocating disk

55
Q

In USP Method 7, the sample holder is a disk and the system is reciprocated ______ (horizontally/vertically). It is used for _____ ______, and the temperature is maintained at ____ +/- ____ degrees C

A

Vertically
Transdermal patches
32 +/- 0.5 degrees C

Drug Delivery II (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions