The regulator issued guidance on the size, shape and other physical attributes of generic tablets and capsules, recommending that the physical characteristics of generic drugs closely resemble those of their reference drugs.

The agency is concerned variations in the physical characteristics of generic drug products – for example, in tablet sizes and shapes – could “affect patient compliance and acceptability of medication regimens” or result in medication errors. The FDA is thus recommending that manufacturers of generic drug products take physical attributes into consideration when developing QTPPs for generic product candidates. The guidance applies to ANDAs and their supplements for additional strengths submitted to the OGD, but not to approved ANDAs already on the market, the FDA notes.

The regulator is making recommendations based on published literature on patient experiences swallowing tablets and capsules, as well as agency experience with NDAs and ANDAs submitted for oral tablets and capsules.

The document provides guidance regarding the size, shape and other physical attributes of tablets and capsules, in addition to biowaivers. With regard to size, the FDA recommends that generic oral tablets and capsules meant to be swallowed intact be of a size similar to that of the respective reference listed drug (RLD). Manufacturers are similarly recommended to ensure the drug products have a similar shape, or to have a shape found to be easier to swallow in comparison to the RLD’s shape. The FDA notes evaluating and comparing the “largest cross sectional areas” of the generic product and the RLD is one way to quantify shape changes, recommending spatial imaging or the use of computer models. The guidance document covers other physical attributes that should be considered as far as how they affect ease of swallowing, including tablet coating, weight, surface area, disintegration time and propensity for swelling.