Extrusion and spheronization in the development of oral controlled-releasedosage forms

The concept of multiparticulate dosage forms was introduced in the 1950s. W ith the increasing use of multiparticulate controlled release (CR) oral dos age forms, in recent times there has been a rise in interest in the methods of preparing these dosage forms. A method that has gained increased usage over the past few years is that of extrusion and spheronization. It has bee n extensively explored as a potential technique and also as a future method of choice for preparation of multiparticulate CR dosage forms. In this rev iew an attempt is made to outline the general process of extrusion and sphe ronization and to assess its importance in the development of multiparticul ate CR oral dosage forms.