ABSTRACT
This chapter focuses on the hard shell capsule formulation involving powders, granules, pellets, and mini-tabs and their combinations. The overall rate of dissolution of drugs from capsules appears to be a complex function of the rates of different processes such as, dissolution rate of the gelatin shell, rate of penetration of the gastrointestinal (GI) fluids into the encapsulated mass, rate at which the mass de-aggregates in the GI fluids, and rate of dissolution of the dispersed drug particles. Both the formulation and the type and conditions of the capsule-filling process can affect the packing density and liquid permeability of capsule contents. The capacity of the capsule is dependent on the density and powder characteristics. The various types of filling machines available to the pharmaceutical industry may be conveniently categorized according to the manner in which the dose of the formulation is measured into capsule body. The methods of dosing for dry powders can be divided into direct and indirect types.
