Process of compressing a tablet

Question 1

when preparing tablets on a single punch press

Answer 1

• appropriately sized die and punches are selected
• lower punch is set at desired level for weight of tablet
• a few tablets are compressed manually and tested for weight and hardness
• lower punch is adjusted to give correct weight
• force applied by the upper punch is adjusted so that tablets are produced with appropriate hardness

Question 2

types of modified release tablets

Answer 2

delayed release( targeted delivery at particular sites, avoids release at particular sites) , immediate release (immediate absorption) and extended/sustained ) release(release drug at controlled manner .

Question 3

types of immediate release tablets

Answer 3

chewable tablets , effervescent tablets, sublingual and buccal tablets, orally disintegrating tablets.

Question 4

Delayed release tablets dependence on

Answer 4

time
- barrier release layers by 1. erosion of gel barrier layer 2. hydration of hydrophilic polymers(the hydrophilic polymer layer is hydrated and the drug us released by diffusing through barrier).
Ph
- eg. enteric coated tablets why? drug can or irritant to stomach or is liable in acidic PH

and enzyme

Question 5

1st technology for extended release forms
dissolution 2 = matrix, encapsulation

Answer 5

matric dissolution system
- produced by compressing the drug with a slowly dissolving matrix into a tablet.
- dissolution is controlled by 1. altering the porosity of the tablet 2. altering the wettablility of the matrix.
Encapsulation
- the drug particle is coated with microencapsulation to form pellets which are then filled into hard gelatin capsules
- once the coating polymer is dissolved the pellet is immediately availbale for dissolution and absorption.
-drug release is determined by the thickness of the polymer coating and dissolution rate.

Question 6

2nd technology for extended release forms
Diffusion 2 = matrix, encapsulation

Answer 6

drug dissolves rapidly but release is controlled by slow rate of diffusion out of the solid dosage form.
1. drug is dispersed as solid particles within a porous matrix (water insoluble polymer)
2. thin water insoluble film surrounding a drug reservoir

Question 7

3nd technology for extended release forms
osmotic pressure controlled system

Answer 7

Simple monolayer tablet consists of an osmotic core (containing drug), a
semipermeable membrane and a microscopic hole acting as a drug
delivery orifice.
* Upon ingestion, water crosses the semipermeable membrane and fill the
core causing it to expand and push the drug through the orifice and into
the GI.
* This release of the drug through the orifice is at a controlled rate and will
stop when the osmotic pressure reaches equilibrium.

Question 8

what are Repeat action tablets

Answer 8

Usually contains 2 doses of the drug: Initial dose of drug is released
immediately and the second dose follows later.
* May be prepared with the immediate-release dose in the outer shell and
the second dose in the tablet’s inner core separated by a slowly
permeable barrier coating