Shah R D, Kabadi M, Pope D G, Augsburger L L
Department of Pharmaceutics, University of Maryland, Baltimore 21201.
Pharm Res. 1994 Mar;11(3):355-60. doi: 10.1023/a:1018996500749.
Extrusion-spheronization is a popular means of producing spheres which can be coated to form a controlled-release system. In the extrusion process, stress is necessary to force a wet mass through small orifices, and as a result, frictional heat builds up at the screen. Therefore, the quantitative measurement of the screen pressure and screen temperature is described and shown to provide objective measures of extrudability. A strain gauge load cell was mounted tangentially to the screen of a Luwa EXDS-60 extruder with a specifically fabricated holder. The load cell output was calibrated in terms of pressure inside the screen with a special rubber plug system. A fast-response thermocouple was used to measure the screen temperature. Experiments with 50/50 lactose/Avicel PH101 revealed that a linear relationship exists between the amount of water used in the granulation and the screen pressure, that the percentage open area of the screen determines the rank order of the screen pressure, and that the maximal yield of 18/25-mesh cut pellets was uniquely related to the screen pressure. Also, a high degree of correlation was observed between the screen pressure and the screen temperature.
挤出滚圆法是生产球体的一种常用方法，所生产的球体可进行包衣以形成控释系统。在挤出过程中，需要施加压力迫使湿物料通过小孔，结果是筛网上会产生摩擦热。因此，本文描述并展示了筛网压力和筛网温度的定量测量方法，以提供挤出性能的客观指标。使用一个特制的支架，将一个应变片式称重传感器切向安装在鲁瓦EXDS - 60挤出机的筛网上。通过一个特殊的橡胶塞系统，根据筛网内部压力对称重传感器的输出进行校准。使用快速响应热电偶测量筛网温度。对50/50乳糖/微晶纤维素PH101进行的实验表明，制粒过程中用水的量与筛网压力之间存在线性关系，筛网的开孔率决定了筛网压力的排序，并且18/25目筛分段颗粒的最大产量与筛网压力具有唯一相关性。此外，还观察到筛网压力与筛网温度之间存在高度相关性。
