Gelatin and Non-Gelatin Capsule Dosage Forms

Capsules offer an alternate to tablets for oral delivery of therapeutic compounds. One advantage of capsules over tablets is their amenability to deliver not only solids but also nonaqueous liquids and semisolids as a unit dose solid dosage form. Shell component is an essential part of capsule dosage forms. Capsule shells, available as hard or soft shells, are formulated from gelatin or a non-gelatin polymeric material such as hypromellose and starch, water, and with or without a nonvolatile plasticizer. The capsule shells may also be formulated to modify the release of their fill contents in a site-specific manner in the gastrointestinal tract. The goal of the current review is to provide an in-depth discussion on polymeric film-forming materials and manufacturing technologies used in the production of capsule shells.