A MULTIPLE-UNIT TABLET FORMULATION FOR MULTILAYER DRUG-COATED GRANULES

Formulation studies were conducted to ascertain the feasibility of des igning a multiple-unit tablet dosage form containing multi-layer drug- coated granules prepared in a fluidized bed process. Compression of th e coated granules into tablets resulted in different release character istics that were dependent on the type and content of the excipients u sed and the compression pressure. An excipient mixture consisting of 3 4.5% w/w microcrystalline cellulose, 2.0% w/w crospovidone and 1.0% w/ w colloidal silicon dioxide was found to be suitable for the tablettin g of the coated granules at a moderate compression pressure. The resul tant tablets, which contained as high as 62.5% w/w of the coated granu les, had a fast disintegrating time (4 to 6 min), reasonable hardness (126 to 135 N) and low friability (less than or equal to 1.0%), satisf ying the prerequisites for a multiple-unit tablet formulation. The tab lets also exhibited in vitro drug release profiles that simulated clos ely, up to 80% total release, those of the constituent uncompressed gr anules.