Hard gelatin capsules, also known as hard-shell gelatin capsules or two-piece capsules, are solid dosage forms in which one or more medicinal agents and/or inert substances are enclosed in a small shell. They are a well-established dosage form that provides solutions to many of today’s drug delivery and nutraceutical formulation challenges.
A hard gelatin capsule shell consists of two prefabricated, cylindrical parts (a cap and a body) each having a spherical, closed end and an open end. The body has a slightly smaller diameter than the cap and fits inside the cap.
Hard gelatin capsule shells are manufactured and supplied empty to the pharmaceutical industry by shell suppliers and then filled in a separate operation. During capsule filling unit operation, the body is filled with drug substance and the shell is closed by bringing the body and cap together.
Hard gelatin capsules are solid dosage forms in which one or more drug substances and/or inert substances are enclosed in a small shell. They are mainly composed of gelatin and consist of two parts: the body designed to contain the drug and liquid, and the cap, which is about half the length of the body. Most capsule products manufactured today are of the hard gelatin type. It is estimated that the use of hard gelatin capsules to prepare solid dosage forms is about 10-fold higher than that of soft gelatin capsules.
Hard gelatin capsules are manufactured and supplied empty to the pharmaceutical industry by shell suppliers and then filled in a separate operation. Making gelatin capsules involves a step-by-step process that requires strict quality control but before we delve into it let’s take a look at the raw materials used in making hard gelatin capsules.