School of Pharmacy, Wenzhou Medical College, Wenzhou, China.
Drug Dev Ind Pharm. 2012 Jun;38(6):670-8. doi: 10.3109/03639045.2011.611809. Epub 2012 Apr 3.
Porosity asymmetric membrane capsules were prepared to study the relationship between the capsule formulation and drug release. Cellulose acetate (CA) and pore formers were used in the capsule shell formulation as the main semipermeable membrane material. The capsules were permeable to both water and dissolved solutes. Using sparingly soluble drug acetaminophen as a model, cumulative release was calculated. The slope of the release profile from the distilled water had good relationship with the concentration of the pore formers F68. The release of acetaminophen was independent to the pH, osmotic pressure of dissolution medium, but influenced by intensity of agitation. When the concentration of pore former was low, zero-order release behavior was observed within 24 h which was consistent with Fickian diffusion model. When the concentration of pore former was high, however, Higuchi model release was found which is caused by Fickian diffusion and osmotic pressure release. With scanning electron microscope (SEM), the surface structure and cross-section of the capsule shell were also studied before and after drug delivery. With simple preparation and broad scope of drug application, porosity asymmetric membrane capsules can give desired drug extended release and show more convenience than controlled tablets with laser drilling.
不对称多孔膜胶囊被制备用来研究胶囊配方与药物释放之间的关系。醋酸纤维素（CA）和致孔剂被用于胶囊壳配方中，作为主要的半透膜材料。胶囊对水和溶解的溶质都具有渗透性。以难溶性药物对乙酰氨基酚（acetaminophen）为模型药物，计算累积释放量。从去离子水中释放曲线的斜率与致孔剂 F68 的浓度之间具有良好的关系。对乙酰氨基酚的释放与 pH 值、溶解介质的渗透压无关，但受搅拌强度的影响。当致孔剂浓度较低时，在 24 小时内观察到零级释放行为，这与菲克扩散模型一致。然而，当致孔剂浓度较高时，发现 Higuchi 模型释放，这是由菲克扩散和渗透压释放引起的。通过扫描电子显微镜（SEM），还研究了药物输送前后胶囊壳的表面结构和横截面。不对称多孔膜胶囊具有简单的制备方法和广泛的药物应用范围，能够实现理想的药物缓释，与激光打孔的控释片剂相比，具有更多的便利性。
