Introduction

SOFT gelatin capsules are one-piece, hermetically sealed soft gelatin shellscontaining a liquid, a suspension, or a semi-solid (Figure 16.1) (Hom and Jimerson, 1990; Wilkinson and Hom, 1990). In contrast to the rigid two-piece hard gelatin capsule shells, soft gelatin capsule shells contain large amounts of plasticizers, which make them flexible. Similar to hard gelatin capsules, they are solid dosage forms intended mainly for oral administration, although they may also be used as rectal or vaginal suppositories. In the late 1980s, a trade association comprised of soft gelatin manufacturers in the U.S. introduced the name “softgels” to further distinguish this dosage form from hard gelatin capsules.