JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD Pharm. D III Year PHARMACEUTICAL FORMULATIONS Previous Question Paper (October/November - 2020 - R08)

Tablets are classified based on their route of administration and method of manufacture. Main types include: oral tablets (compressed, multiple compressed, sugar-coated, film-coated, enteric-coated, buccal, sublingual, chewable), tablets administered in body cavities (vaginal, rectal), and tablets for solutions (effervescent, dispensing, hypodermic).

The formulation of tablets involves the selection of excipients to ensure stability, bioavailability, and manufacturability:

1. Diluents/Fillers: Inert substances like lactose, microcrystalline cellulose, or starch added to increase bulk.
2. Binders/Adhesives: Agents like acacia, PVP, or starch paste used to promote granule cohesion.
3. Disintegrants: Materials like croscarmellose sodium or starch that facilitate tablet breakup in the GI tract.
4. Lubricants/Glidants: Substances like magnesium stearate or talc added to reduce friction during ejection and improve powder flow.
5. Coloring and Flavoring Agents: Added to improve aesthetic appeal and patient compliance.

Sugar coating is a traditional, multi-step process used to mask the unpleasant taste or odor of drugs and protect them from environmental factors. The process involves the following stages:

1. Sealing (Waterproofing): Application of a moisture-resistant polymer (e.g., shellac or cellulose acetate phthalate) to prevent water from the coating syrup from penetrating the tablet core.
2. Sub-coating: Application of adhesive binders and dusting powders (e.g., calcium carbonate, talc) to build up the tablet size and round the edges.
3. Smoothing (Syrup Coating): Application of a simple sugar syrup to provide a smooth, white surface.
4. Coloring: Addition of water-soluble dyes or pigments to the syrup to achieve the desired aesthetic.
5. Polishing: Final step using a wax (e.g., carnauba or beeswax) in a polishing pan to provide a high-gloss finish.