Solid Oral Modified Release Dosage Forms

Question 1

What are the various types of Modified-Release Dosage Forms?

Answer 1

-extended release
-delayed release
-repeat action
-targeted release

Question 2

Extended Release

Answer 2

any drug where its release is prolonged for an extended period of time

Question 3

Delayed Release

Answer 3

EC tablets –released in the intestinal area

Question 4

Repeat Action

Answer 4

2 complete doses of a drug (same or different) that release at different times. One immediate release and the other extended release

Question 5

Why were extended-release drugs made?

Answer 5

Intended for drugs that are unstable in the stomach acid or drugs that can cause irritation to the stomach

Question 6

Targeted Release

Answer 6

Delivering drugs directly to one site of action; GI –some forms for the colon or other specific ailments

Question 7

Advantages of modified-release dosage forms

Answer 7

-extended release-minimizes fluctuation in drug blood levels
-reduces dosage frequency
-enhances convenience and compliance (less doses for pt to take)
-Reduces adverse effects (less chance for toxicity when given in an ER form)
-Reduces overall healthcare costs (due to lack of nonadherence)

Question 8

Disadvantages of modified-release dosage forms

Answer 8

-loss of flexibility in adjusting the drug dosage or dosage regimen
-Run the risk of sudden and total drug release (dose dumping)
-difficult to remove the drug from the system in case of intoxication
-not practical for drugs requiring higher doses in conventional forms (if dose if too high, the tablet size would need to increase and will be too big)
-DO NOT CUT IN HALF: will alter release of drug and may not receive full dose

Question 9

Requirements for a drug to be considered an extended-release dosage form

Answer 9

-shouldn’t have very slow or very fast rate of absorption (if drug has a slow absorption and elimination, will take its time to get into the blood and leave the body
-should have uniform absorption from GI tracts
-Should have a relatively low therapeutic dose
-Should have a good margin of safety (if accidental dose dumping occurs, should have wide window so won’t pass toxicity range)
-Should be intended for chronic therapy (provide longer duration of action)

Question 10

Various technologies/formulations of extended-release dosage forms

Answer 10

-Coated beads, granules, and microspheres
-Multi-tablet systems
-Microencapsulated drug
-Enbedding drug in slowly eroding of hydrophilic matrix-Embedding drug in inert plastic matrix
-Complex formation
-Ion exchange resins
-Osmotic pumps

Question 11

Coated Beads, Granules, and Microspheres

Answer 11

Different color beads; one color is for immediate release and the other is coated for extended-release. The thickness of the coating will determine the rate of release
-Nasogs

Question 12

Multi-tablet systems