Excipients in tableting

Question 1

Advantages of oral dosage forms

Answer 1

safe, stability, accurate drug dosing, convenient, low cost

Question 2

Fillers / diluents
what do they do and example

Answer 2

Increase bulk volume / size, used in low drug doses, e.g. Lactose, dicalcium phosphate

Question 3

SUPER disintegrates - what do they do and examples

Answer 3

Added to ensure that the tablet will break up into small fragments when in contact with liquid so to promote rapid drug dissolution.

sodium starch glycolate, croscarmellose

Question 4

Mechanisms of disintegration

Answer 4

Mechanisms of disintegration:
Uptake of water induces capillary forces
Swelling
Release of gas to disrupt the tab
Enzymatic lysis of the binder

Question 5

d. Tablet disintegration via enzymatic lysis of binder

Answer 5

Addition of small quantities of appropriate enzyme may be sufficient to produce rapid disintegration.

Also, enzymes present in the body act as disintegrants. These enzymes destroy the binding action of binder and helps in disintegration.

Question 6

Binders (dry and wet):

Answer 6

increase the mechanical strength

e.g. PVP, HPMC, gelatin, starch, glucose, sucrose, water /ENZYMES

Question 7

Antifrictional agents:

Answer 7

Lubricants: Intermediate layer between tablet mix and die wall e.g. sodium benzoate, talc, magnesium stearate

Glidants: Improve flow properties, adsorb onto surface of bulk powder e.g. colloidal silica, cornstarch, talc

Antiadherants: Reduce adhesion between powder and punch faces e.g. talc, corn starch, magnesium stearate (PREVENT PICKING!!)

Question 8

Dissolution modifiers

Answer 8

e.g. pH modifiers Betaine chloride, fumaric acid, and tartaric acid

Question 9

Absorbents:

Answer 9

Absorb fluids in dry state e.g. MCC and silica

Question 10

Flavouring agents

Answer 10

Improve / mask taste e.g. dextrose, mannitol, sucrose, saccharin

Question 11

Colouring agents:

Answer 11

Enhance aesthetics / identification / patient compliance e.g. aluminium hydroxide

Question 12

Wetting agents

Answer 12

Enhance penetration of liquid and thus solubility by lowering surface tension e.g. sodium lauryl sulfate

Question 13

Antioxidants:

Answer 13

Reduce free-radical damage and oxidation of formulation thus improving stability e.g. ascorbic acid

Question 14

Preservatives:

Answer 14

inhibit microbial growth e.g. methylparaben, propylparaben