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

The presence of water is an essential feature of formulations containi ng mirocrystalline cellulose (MCC) for the preparation of spherical gr anules by the process of extrusion/spheronisation. The current work pr ovides further proof of this observation. Formulations consisting of M CC and either a coarse (118.0 mum) or a fine grade (18.0 mum) of lacto se mixed with two levels of water have been examined as they spheronis e and after collection and drying. The shape changes on the plate, plu s the size and shape changes, as a function of spheronisation time, sh ow that the mixtures containing fine particle size will form good sphe res at either 33 or 37% water content, but the mixtures containing the coarse particle size will only form controlled size spheres at 33% mo isture content. The results were found to be equivalent for both 1.0 a nd 1.5 mm extrudates. The effect can be related to the mobility of the water in the different packing structures produced by the different p article sizes of lactose.