Modified Release Dosage Forms

Question 1

What is a sustained release system?

Answer 1

include any drug delivery system that achieves slow release of drug over extended period of time

Question 2

What is a controlled-release system

Answer 2

If a sustained-release system is successful at maintaining constant drug levels in the target organs, it is considered a controlled-release system

Question 3

What is a prolonged-release system.

Answer 3

If the sustained-release system prolongs therapeutic levels of the drug it is considered a prolonged-release system.

Question 4

What is a Extended release systems

Answer 4

allow reduction in dosing frequency from that necessitated by a conventional dosage form (FDA definition).

Question 5

What is a Delayed release systems

Answer 5

release the drugs at a time other than promptly after administration. The delay may be influenced by pH (like enteric coated formulations).

Question 6

What is a Targeted release

Answer 6

isolates or concentrates the drugs in a specific body region, tissue or organ e.g. tumors Nanomedicine – targeted drug delivery

Question 7

What is a Repeat action

Answer 7

forms usually contain two or more single doses of the drug, one for immediate release and the second for delayed release

Question 8

What is Conventional dosage form

Answer 8

Normal take a pill it has an action and it metabolizes normally

Question 9

What are the examples for preparing delayed action formulation?

Answer 9

• Entric coated
• Rheumatoid Arthritis
• Morning Sickness

Question 10

XL products provide

Answer 10

an immediate release of drug, which promptly produces the desired therapeutic effect, which then is followed, by the gradual, and continual release of additional amounts of drug to maintain its effect over a period of time.

Question 11

Sustained plasma levels provided by XL drug products often

Answer 11

eliminate the need for night dosing

Question 12

What is the difference between Immediate Release/Sustained Release and extended-release?

Answer 12

Immediate has a shorter duration as compared to Sustained release, and Extended-release has a longer duration compared to the two

Question 13

What are a few design variabilities in MRDFs that need to be considered?

Answer 13

a) Route of delivery
b) Type of delivery system
c) Disease being treated
d) The patient
e) Length of therapy
f) Properties of the drug
-physicochemical -biological

Question 14

What are drug candidates for MRDFs?

Answer 14

Solubility

Partition Coefficient (move between membranes)

Stability (In and out)

Rate of absorption

Ability of drugs for complexation

Good margin of safety

Used for chronic conditions rather than acute

Dose

Question 15

What solubility is MRDF not possible?

Answer 15

<0.01

Question 16

What property affects the ability of the drugs to diffuse through the polymers used in the design of MRDFs

Answer 16

Partition coefficient

Question 17

Slow kinetics

Answer 17

not necessary to prepare MRDFs

Question 18

Fast kinetics

Answer 18

very large amounts will be required to design MRDF

Question 19

Narrow therapeutic window

Answer 19

Not suitable due to product defect or incorrect administration

Question 20

What is the maximum dose size for oral formulations?

Answer 20

0.5-1gram

Question 21

What are the two categories of dissolution systems?

Answer 21

a) Membrane dissolution systems
b) Matrix dissolution systems

Question 22

What is Membrane Dissolution Systems?

Answer 22

Different groups of particles have different membrane thicknesses that dictate their release

or

Layers of sugar and drug

Question 23

What are matrix dissolution systems?

Answer 23

Drug is dispersed with different sized granules that have different dissolution times

Usually in the form on a tablet/capsule where hydration releases it

Question 24

What is a diffusion system?

Answer 24

Release rate of a drug is determined by its diffusion through a water-insoluble polymer (Coating)

Question 25

Two types of diffusion devices

Answer 25

Membrane Diffusion (Reservoir devices)
(core is surrounded by a polymeric membrane).

Matrix Diffusion (Matrix device) (drug is distributed uniformly in an inert polymeric matrix).

Question 26

Dissolution

Answer 26

a drug that is located inside the reservoir which is released

Question 27

Diffusion

Answer 27

of drug across membrane - rate controlling step.

Question 28

Matrix Diffusion Devices

Answer 28

Drug is dispersed homogenously in the matrix which DOES NOT dissolve or erode

Diffusion of the drug from the matrix to outsideà Rate limiting step

Capsule will be excreted

Question 29

Membrane-Matrix Hybrid example

Answer 29

IUD

Question 30

What are OSMOTIC SYSTEMS?

Answer 30

Osmotic pressure can be employed as the driving force to generate a constant release of drug, provided that constant osmotic pressure is maintained.

Water comes in and pushes drug through a small hole