Pearnchob Nantharat, Bodmeier Roland
College of Pharmacy, Freie Universitat Berlin, Berlin, Germany.
Eur J Pharm Biopharm. 2003 Nov;56(3):363-9. doi: 10.1016/s0939-6411(03)00121-8.
Drug-layered pellets were coated with micronized polymer powders (Eudragit) RS, ethylcellulose, and shellac) by a dry powder coating technique as an alternative to organic- and aqueous-based coatings (Eudragit) RS 30D, Aquacoat) ECD) were investigated. High plasticizer concentrations (40%) and a thermal after-treatment (curing) were necessary for the coalescence of the polymer particles and good film formation. Ethylcellulose required a higher curing temperature and time than Eudragit) RS because of its higher glass transition temperature (133 versus 58 degrees C). A smaller polymer particle size also promoted film formation. In general, pellets coated with polymer powders required higher coating levels to obtain similar drug release patterns as pellets coated with organic polymer solutions and aqueous polymer dispersions.
采用干粉包衣技术，用微粉化聚合物粉末（尤特奇RS、乙基纤维素和虫胶）对含药微丸进行包衣，作为有机基和水基包衣（尤特奇RS 30D、水分散体包衣材料）的替代方法进行了研究。为使聚合物颗粒聚结并形成良好的薄膜，需要高浓度增塑剂（40%）和热后处理（固化）。由于乙基纤维素的玻璃化转变温度较高（133℃对58℃），因此与尤特奇RS相比，它需要更高的固化温度和时间。较小的聚合物粒径也有利于薄膜形成。一般来说，与用有机聚合物溶液和水性聚合物分散体包衣的微丸相比，用聚合物粉末包衣的微丸需要更高的包衣量才能获得相似的药物释放模式。
