Lecture 6- Tableting I

Question 1

Tablet production

Answer 1

-powders intended for compression into tablets must possess 3 essential characteristics;

*powder flowability
- material can be transported through the hopper into the die = produce tablets of consistent weight and drug dose
- powder flow can be improved= glidant/ granulation

*powder compressibility
- ability of powder to deform under pressure

*powder compatibility
- the property of forming a stable, intact compact mass when pressure is applied

Question 2

Tablet manufacturing

Answer 2

• direct compression, wet/dry granulation

^choice of method depends on;
-size of dose, flowability of drug, compressibility, compatibility and stability characteristics of the drug

Question 3

Starting point; dose of drug

Answer 3

*low dose (<25mg)
-most of the tablet will be excipients; check content uniformity

*high dose (>250mg)
-most of the tablet will be drug; check compatibility + flowability

Question 4

Lower dose drugs= directly compressed

Answer 4

Blend —> compress

-can compensate for any lack of compactibility/ lack of flowability by the use of special direct compression fillers

-can provide lubricity by addition of die wall lubricant
-can help fluidity by adding a glidant
-assure rapid disintegration by adding diksintegrant

Question 5

General formula for a direct compression tablet

Answer 5

Slide 11

Question 6

Advantages of direct compression

Answer 6

*economical = less time, space, materials, personnel, fewer steps
- elimination of heat + moisture of wet granulation = increased stability
*increased particle dissolution rate
*batch-to-batch variation is negligible
*fewer excipients= less chance of chemical interaction between drug + excipients

Question 7

Disadvantages of direct compression

Answer 7

-problem of content uniformity for low dose drugs
-segregation of low dose drugs
-drug is fluffy= poor flow and compression
-small-medium dose drugs difficult to tablet to small final weight
-requires tight control over physical properties of filler-binder
Cost- fillers are more expensive when used in granulation
-punch wear
-dustiness
-static electricity

Question 8

Requirements for a directly compressible filler

Answer 8

-good flowability
-good blending properties
-low lubricant sensitivity
-high compactibility
-inertness
-constant quality
-relatively cost effective

Question 9

Examples of direct compression filler-binders

Answer 9

*microcrystalline cellulose
-most compressible/compactable material available
-tablets self disintegrate and require little lubricant

*spray processed lactose
-mini granulation of lactose crystals glued together by small amount amorphous lactose

Question 10

Direct compression- not practical

Answer 10

-large dose, poorly compressible/compactable
Granulate;
-improves flowability
-addition of a binder = glues the particles together into granules to hold the tablet together = improves compactibility