ABSTRACT
Recent decades have seen tremendous strides in the designing of novel dosage forms, but tablets still remain an attractive option for pharmaceutical scientists and clinicians because they offer advantages of accurate unit-dosing, better patient compliance, ease of large-scale manufacturing, and low production cost (1). The formulation of a tablet involves combining the active ingredient, the ‘‘drug,’’ with pharmacologically inactive ingredients called ‘‘excipients.’’ National Formulary Admission Policy of 1994 (2) defines excipient as ‘‘any component other than the active substance(s) intentionally added to the formulation of a dosage form.’’ Excipients aid in the manufacturing and performance of a dosage form, and serve different purposes as diluent, binder, disintegrant, glidant, and lubricant. Thus, excipients can be called as the ‘‘functional components’’ of a formulation (3). The total market for excipients is estimated to be US $2.5 billion with an average annual growth of 7% to 8% in volume and 4% to 5% in value (4). The overall contribution of excipients in dosage form designing can be better appreciated from the fact that more than 70% of the formulations contain excipients at a concentration higher than the drug (5). It is now well established that excipients contribute critically toward processing, stability, safety, and performance of solid dosage forms (Table 1).
