ABSTRACT
Capsules are solid dosage forms with hard or soft gelatin shells of various shapes and sizes, usually containing a single drug substance and a number of excipients formulated to provide a consistent fill weight and therapeutic relief when administered to a patient. The soft shell gelatin capsule originated in France when Mothes, a French pharmacist, was granted a patent in 1833. The first reference to the hard shell two piece capsule was made in 1848 when Murdoch, a London patent agent, was granted a patent. Hard shell capsules permit the choice of a single drug or combination of drugs at the exact dosage level required by the patient who very often finds swallowing a capsule easier than a tablet. The hard shell capsule is often referred to as the dry filled capsule (DFC) but with the development of new formulation techniques and the improvement in the closing mechanism of the cap and body, oils and pastes may now be filled. Considerable improvement in the equipment used for this process has led to renewed interest, and Eli Lilly & Co. (the empty capsule manufacturing and marketing operation of Eli Lilly has now been taken over by Shenogi, the Japanese company) has held symposia on this topic devoted to the presentation of papers on formulation and machine demonstrations. The first British pharmaceutical product using this type of formulation was Colpermin.
