Abstract: A solid pharmaceutical composition suitable for oral or rectal administration comprising a unit dosage of a pharmaceutically active ingredient (and optionally one or more inert fillers) homogeneously dispersed in a pharmaceutically acceptable binder, wherein at least a major portion (i.e., at least 50% by weight) of the binder is a microcrystalline solid phase prepared by raising the pH of a dairy whey lactose permeate having a pH below about 7 to a pH between about 8 and 10 to form (i) a lactose-rich aqueous solute phase capable of being autoclaved for 10-20 minutes at 121.degree. C.