FILM-FORMING POLYMER-GRANULATED EXCIPIENTS AS THE MATRIX MATERIALS FOR CONTROLLED-RELEASE DOSAGE FORMS

Lactose and dibasic calcium phosphate (DCP) were granulated with vario us concentrations of film-forming polymers by a stepwise spraying meth od to prepare a directly compressible matrix excipient. The film-formi ng polymeric latex of Eudragit RS-SOD, Eudragit RL-30D, and Surelease (ethylcellulose) were used in this study as the source of the granulat ing materials. Better flowability and compressibility were observed fo r all the granulated particles than the polymer-free granules. Most ta blets prepared from the polymer-granulated particles exhibited satisfa ctory friability of less than 1% except for those prepared from lactos e particles granulated with low concentrations of ethylcellulose and f rom plain lactose granules. Change in tensile strength and tablet thic kness were in good agreement with the plasticity of the granulating po lymer. Polymer granulated lactose and DCP provided for controlled rele ase of captopril from matrix tablets. This investigation suggests that conventional excipients can be modified by a simple granulating proce dure to provide better physical properties for being used as a matrix material. (C) 1998 Elsevier Science B.V.