3.DISINTEGRANTS: These are substances added to tablets to promote breaking or fragmentation of tablets into smaller fragments in the GIT. This increases the surface area and enhance invivo absorption of the drug.
E.g. of disintegrants:starch and derivatives, microcrystalline cellulose, sodium carboxymethylcellulose, sodium lauryl sulphate, certain enzymes, etc.
4.LUBRICANTS: These are added to tablet formulations to reduce the tendency of granules to adhere to punching surfaces. They are added to:
Prevent the granules adhering to the punches (anti-adherrance).
Reduce the friction between the tablet and the dye wall. This facilitates smooth ejection of tablet from the dye cavity.
E.g. of lubricants are: Magnessium stearate.
NON-BASIC/MINOR EXIPIENTS
COLOURING AGENTS(COLOURANTS): These are usually added to the tablet formulation for a no. of reasons
To make the tablet more elegant. This makes the patient likes it.
To hide or mask unpleasant colour of the drug.
As a means of identification e.g. for different companies and manufacturers.
FLAVOURING AGENTS: These are normally used to mask disagreeable odours in order to add flavour to the drug. This is also to make the drug more palatable. They are volatile oils from Cinnamon, Anise, peppermint, clove, lemon and orange.
SWEETENING AGENTS: These are added to tablets particularly those that stay for sometime in the mouth (sublingual, chewable tablets) etc to mask unpleasant taste and to make the tablets palatable. E.g. sucrose, lactose, mannitol, aspartame (used in Losenges).
ADSORBENTS: These are substances that absorb small quantity of liquid (water) and remain in the dry state. The purpose of adding this is:
To protect the hygroscopic material from absrobing water from the atmosphere
For absorption of volatile oils used as flavours.
For absorption of oily and liquid extracts in a formulation.
E.g. silicon dioxide,Magnessiumcarbonate and Magnessium oxide
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