PROLONGED RELEASE MATRIX PELLETS PREPARED BY MELT PELLETIZATION .1. PROCESS VARIABLES

A melt pelletization process was investigated in an 8 litre laboratory scale high shear mixer using a formulation with paracetamol, glyceryl monostearate 40-50, and microcrystalline wax. The effects of jacket t emperature, product temperature during massing, product load, massing time and impeller speed were investigated by means of factorially desi gned experiments. The maximum yield of pellets in the range of 500 - 1 400mum was found to approx. 90%. For process conditions preventing dep osition of moist mass, the process was found to be reproducible. Impel ler speed and massing time were found to be important process variable s. Remarkably low in vitro drug release rates were observed in USP-dis solution tests.