Generic drugs must be bioequivalent to a reference listed drug (RLD), but physical attributes also play a role in FDA approval. Last week, the FDA released draft guidance entitled “Size, Shape, and Other Physical Attributes of Generic Tables and Capsules.” The guidance encourages generic manufacturers to develop tablets and capsules of similar size to the RLD, and sets several benchmarks as to how much larger in dimension and volume a generic product can be relative to its RLD. In several instances, the FDA has not approved a generic drug due to physical attributes that could adversely affect patient outcomes (e.g., the generic version not as easy to swallow as the RLD, which could reduce adherence and drug release). Overall, the FDA aims to promote adherence and reduce medication error by encouraging similar physical appearances between brand and generic drugs.
The guidance will only apply to new generic drugs, not ones are already on the market. It places new restrictions on generic drug manufacturers, who need to mimic the physical attributes of a brand drug without infringing on intellectual property. Trade dress, a subset of trademark law, allows drug manufacturers to claim ownership of the physical characteristics of their product, such as size, shape, flavor, aroma, and color scheme. While public health concerns can trump trade dress in court, claims of trade dress have been a tool for drug manufacturers to delay generic competition.