Law M F, Deasy P B
University of Dublin, Ireland.
Eur J Pharm Biopharm. 1998 Jan;45(1):57-65. doi: 10.1016/S0939-6411(97)00123-9.
Microcrystalline cellulose 19 parts was combined with sodium carboxymethylcellulose, hydroxypropylmethyl cellulose, hydroxypropyl cellulose or polyvinylpyrrolidone one part, either by spray-drying or physical mixing. This combined excipient (20%) mixed with lactose (80%) and water was added to aid formation of pellets by the process of extrusion-spheronization. Spray-dry combined excipient produced pellets with higher yield, better sphericity and improved tolerance to minor variation in the level of water added, compared with the physical mix excipient. Physicochemical testing based on scanning electron microscopy with energy dispersive analysis, differential scanning calorimetry and X-ray diffraction analysis, indicated that the spray-drying with the hydrophilic polymer caused disintegration of the microcrystalline cellulose component into smaller crystallites, favouring its more uniform dispersion throughout the lactose during subsequent processing. The hydroxypropyl cellulose or polyvinylpyrrolidone containing excipients were the most satisfactory of the hydrophilic polymers examined, because they had the least adhesive strength favouring maximum yield of highly spherical pellets.
将19份微晶纤维素与1份羧甲基纤维素钠、羟丙基甲基纤维素、羟丙基纤维素或聚乙烯吡咯烷酮通过喷雾干燥或物理混合的方式进行混合。将这种混合辅料（20%）与乳糖（80%）及水混合，通过挤出滚圆法辅助制备微丸。与物理混合辅料相比，喷雾干燥混合辅料制备的微丸收率更高、球形度更好，并且对加水量的微小变化具有更好的耐受性。基于扫描电子显微镜能谱分析、差示扫描量热法和X射线衍射分析的理化测试表明，亲水性聚合物喷雾干燥导致微晶纤维素组分崩解为更小的微晶，有利于其在后续加工过程中更均匀地分散在乳糖中。在所研究的亲水性聚合物中，含羟丙基纤维素或聚乙烯吡咯烷酮的辅料最为理想，因为它们的黏附力最小，有利于获得高球形度微丸的最大收率。
