Hard gelatin capsules are a common oral solid dose for immediate release formulations. Compared to tablets they are easy to formulate and manufacture, formulations can be developed with minimal amounts of active pharmaceutical ingredient (API) and they are easily blinded for clinical trial purposes. Additionally they provide a ready means of identification through the choice of capsule shell colour and printing, and they are patient friendly being easy to swallow and providing taste masking for unpleasant actives.
Lactose and MCC are common diluents in hard gelatin capsules. The most suitable types of MCC would be Pharmacel® 101 grade. The most suitable types of Lactose in hard gelatin capsules would be SuperTab® 21AN, SuperTab®30GR and sieved grades of Pharmatose®.