Deck 6: Controlled Drug Delivery

Question 1

What happens when drugs administered by a conventional dosage form have high rate of absorption and elimination?

A) Drugs are absorbed slowly
B) Drugs have lower C_max
C) Drugs have longer plasma half life
D) Drugs have shorter duration of action

Answer 1

D

Question 2

MTCp is

A) Maximum therapeutic concentration
B) Minimum therapeutic concentration
C) Minimum toxic concentration
D) Maximum toxic concentration

Answer 2

C

Question 3

What happens when the rate of drug release equals drug absorption in a controlled drug delivery system?

A) The drug achieves a steady state concentration
B) Results in a flat Cp vs. T profile
C) Maintains constant Cp within in the therapeutic window of the drug
D) All of the above

Answer 3

D

Question 4

What is the primary goal of controlled drug delivery systems?

A) Maintain drug plasma concentration of drugs with narrow therapeutic windows at safe therapeutic levels
B) Reduce dosing frequency
C) Improve patient compliance
D) All of the above

Question 5

What is the rate limiting step for drug absorption in controlled drug delivery systems?

A) Dosage
B) Route of administration
C) Drug release rate
D) Dosing frequency
E) Patient age

Question 6

Which of the following affect drug release rate? More than one answer may be correct.

A) Route of administration
B) Patient weight
C) Polymer degradation
D) Color of dosage form

Question 7

Drug release rate from a reservoir system depends on: (More than one answer may be correct.)

A) Drug solubility in ethanol
B) Porosity and tortuosity of rate controlling membrane
C) Drug solubility in polymer matrix
D) Osmotic pressure

Question 8

Which of the following are examples of reservoir system? More than one answer may be correct.

A) Retisert
B) Zoladex
C) Geomatrix
D) Duragesic

Question 9

Which of the following are diffusion controlled drug delivery systems? More than one answer may be correct.

A) Single compartment osmotic pump
B) Monolithic systems
C) Dilacor XR
D) Reservoir systems
E) Mirena

Question 10

Which of the following is a type of erosion? More than one answer may be correct.

A) Surface erosion
B) Internal erosion
C) Lateral erosion
D) Bulk erosion

Question 11

In erosion controlled systems,the drug is

A) Coated on a polymer matrix
B) Encapsulated in a polymer matrix
C) Released through a rate controlling membrane
D) Dissolved in a polymer

Question 12

During "burst phase"

A) Dosage form bursts
B) Surface bound drug is released
C) Drug is not released
D) None of the above

Question 13

What is self-healing?

A) Treating oneself without consulting a physician
B) Healing without taking medication
C) Pore closure
D) All of the above

Question 14

What happens when a swelling controlled system is exposed to aqueous environment?

A) Polymer matrix softens and turns into a gel
B) Swelling propagates outwards radially
C) Polymer chains entangle forming compact matrix
D) The swollen and non-swollen matrices move close to each other

Question 15

The initial drug release in swelling controlled systems follows both fickian and non-fickian kinetics.

Question 16

Initial drug release from a bulk eroding polymeric matrix depends on

A) Surface pores formed due to water penetration
B) Aqueous solubility of drug encapsulated
C) Size of drug molecules
D) All of the above

Question 17

Viadur is an example for which of the following drug delivery systems?

A) Monolithic release systems
B) Reservoir system
C) Implantable osmotic pump
D) Swellable controlled systems

Question 18

Briefly explain what happens during the lag phase of release in a bulk eroding system.

Question 19

Why is surface erosion tough to achieve in erosion controlled systems?

Question 20

What is the rate-limiting step for drug absorption in controlled drug delivery systems?

Question 21

What are the major factors that govern the drug release from reservoir systems?

Question 22

What is an implantable osmotic pump? Briefly explain the release mechanism in 'osmosis controlled systems' with examples.

Question 23

Explain the mechanism of drug release from monolithic systems.

Question 24

In surface erosion controlled systems,the rate of erosion remains constant throughout the erosion process.

Question 25

What is the rate limiting step of drug release from bulk erosion system during initial burst release phase?

A) Drug diffusion through pores
B) Erosion of polymer matrix
C) Polymer chain relaxation
D) Disintegration of eroded matrix

Question 26

Fill in the blank: Upon hydration,the polymer chains relax in a swelling controlled drug delivery system because of reduction in the ___ of the polymer.

Question 27

In a swelling controlled drug delivery system,the swelling begins at the inner layer and radially moves outward as water penetrates the system. (True or False)

Question 28

Fill in the blank: The moving boundary that separates swollen matrix from nonswollen matrix in a swelling controlled drug delivery system is known as the ____.

Question 29

Glumetza is a swelling-based gastroretentive formulation of metformin hydrochloride for the treatment of type 2 diabetes. What can be done to maximize the gastric retention and drug bioavailability?

A) Administer tablet on empty stomach
B) Administer tablet with food
C) Administer tablet after meal

Question 30

Fill in the blank: Duros system is an implantable osmotic pump drug delivery system,which contains excess sodium chloride concentration in the engine to maintain osmotic pressure and the subsequent ___ constant.

Question 31

Fill in the blank: The rate of drug release in an osmotic pump delivery system remains constant as long as there is an ___.