Encapsulation refers to a range of dosage forms in a relatively stable shell known as a capsule. Whereas soft-shelled capsules (single-piece gel encapsulation) are primarily used for oils and active ingredients that are dissolved or suspended in oil, hard-shelled capsules (two-piece gel encapsulation) typically contain dry, powdered ingredients or miniature pellets. Hard-shelled capsules are made in two halves: a smaller-diameter "body" that is filled and then sealed using a larger-diameter "cap". The powder or spheroids inside the capsule contains the active ingredient (API) and any excipients.
Quality control tests
The following tests are routinely performed for capsules with SOTAX instruments: