Abstract

A multiple unit oral pharmaceutical dosage form having a plurality of pellets in a water soluble capsule or in a tablet compressed from the pellets, wherein each pellet contains (a) a substantially inert core, (b) an active ingredient layer over the inert core, and containing (i) a pharmacologically active particulate active ingredient, (ii) a nonembedding amount of a binder for adhering the active ingredient over the inert core, and optionally (iii) a pharmaceutically acceptable, inert adjuvant, such as colloidal silica, and (c) a coating over the active ingredient layer for retarding the release of the active ingredient from the active ingredient layer into an aqueous body fluid solvent in situ, the nonembedding amount of the binder is suitably from about 1% wt. to about 10% wt. based on the active ingredient layer, the binder in the active ingredient layer is suitably a mixture of ethylcellulose and shellac, in a weight proportion suitably of from about 1:9 to about 9:1, the coating for retarding the release suitably contains from about 70% wt. to about 95% wt. based on the coating, of a substantially water-insoluble, pharmacologically inert, particulate material, and a binder; the pharmacologically inert, particulate material is suitably talcum, and the binder in the active ingredient layer is suitably identical to the binder in the coating.