THE INFLUENCE OF MOISTURE-CONTENT ON SPHERONIZATION OF EXTRUDATE PROCESSED BY A RAM EXTRUDER

The presence of water is an essential feature of formulations containing mirocrystalline cellulose (MCC) for the preparation of spherical granules by the process of extrusion/spheronisation. The current work provides further proof of this observation. Formulations consisting of MCC and either a coarse (118.0 mum) or a fine grade (18.0 mum) of lactose mixed with two levels of water have been examined as they spheronise and after collection and drying. The shape changes on the plate, plus the size and shape changes, as a function of spheronisation time, show that the mixtures containing fine particle size will form good spheres at either 33 or 37% water content, but the mixtures containing the coarse particle size will only form controlled size spheres at 33% moisture content. The results were found to be equivalent for both 1.0 and 1.5 mm extrudates. The effect can be related to the mobility of the water in the different packing structures produced by the different particle sizes of lactose.