A COMPARISON BETWEEN THE EXTRUSION FORCES AND SPHERE QUALITY OF A GRAVITY FEED EXTRUDER AND A RAM EXTRUDER

The forces involved during extrusion of mixtures of various proportions of excipients of different solubility, microcrystalline cellulose and water were compared on an instrumented ram extruder and an instrumented gravity feed extruder. The difference between the two extruders is that a gravity feed extruder is a discontinuous system while the ram extruder is a continuous system. The extrusion forces recorded with the ram extruder were always greater than those with the. gravity feed extruder. The quality of the spheres produced by the two different extruders was compared. For an equivalent quality a lower water content was required for formulations processed by the ram extruder.