CAPSULES

There are two forms of capsules, hard capsules and soft capsules. Hard capsules are for
powders or semi-solid preparations and soft capsules for liquids.
Sizes of Hard Capsules, From The Art of Dispensing, 1937
Hard capsules were invented in 1833 in France. They were (and are today) made of gelatin
and consist of two parts, a body and a lid (they were supplied ready made but were filled in the
pharmacy). A simple filling apparatus would consist of a wooden base, drilled with holes
equivalent to the size of capsule being used. Weighed powder doses could be introduced
through a small funnel. Semi-solid preparations were rolled into a pipe, a piece cut off and
weighed, trimmed to the correct weight and placed in a capsule. The caps were fitted and the
capsules packed and labelled.
Soft capsules could be made in the pharmacy. The apparatus was called a dipper and
consisted of metal moulds of various sizes which were set into a base. The dipper was inverted
and dipped into a melted glycerin/gelatin mixture, placed on its base and, when cool, the
capsules were removed. The capsules could then be filled with a measured amount of liquid via
a syringe then closed with a blob of the molten glycerin/gelatin mixture applied with a glass rod,
or sealed by careful application of a heated rod.