Department of Pharmaceutics and Analytical Chemistry, University of Copenhagen, Denmark.
Int J Pharm. 2011 Sep 30;417(1-2):245-55. doi: 10.1016/j.ijpharm.2011.03.002. Epub 2011 Mar 15.
With the increasing interest in lipid and surfactant based drug delivery systems (LSBDDS) for oral delivery of poorly soluble drugs, the need for efficient development tools is emerging. In vitro lipolysis models, simulating the digestion in the small intestine, is a promising tool in this regard. Several different in vitro lipolysis models have been used for characterization of LSBDDS, all using porcine pancreatin as lipase source, and primarily differing in the addition scheme of calcium and the kind of bile acids employed. Both calcium and bile influence the lipolysis. Calcium have been used both as fixed addition at the beginning of the experiment and with a continuous addition during lipolysis. Both pure bile acids and crude porcine bile extract have been used. Lipolysis of LSBDDS will generate mixed micelles, as well as lamellar and hexagonal phases. These have been characterized by dynamic light scattering, cryogenic transmission electron microscopy and small angle X-ray scattering. The faith of drug during in vitro digestion of a LSBDDS is often studied by ultracentrifugation and quantification of drug in the different phases formed. Further, drug precipitated during in vitro lipolysis has been characterized by X-ray powder diffraction and polarized light microscopy.
随着人们对基于脂质和表面活性剂的药物传递系统（LSBDDS）用于口服递药的兴趣日益增加，对高效开发工具的需求也日益显现。模拟小肠消化的体外脂肪分解模型是这方面很有前途的工具。已经使用了几种不同的体外脂肪分解模型来对 LSBDDS 进行特性描述，所有模型均使用猪胰酶作为脂肪酶来源，主要区别在于钙的添加方案和所使用的胆汁酸种类。钙和胆汁都会影响脂肪分解。钙既可以在实验开始时作为固定添加物，也可以在脂肪分解过程中连续添加。既使用了纯胆汁酸，也使用了猪胆提取物。LSBDDS 的脂肪分解会产生混合胶束，以及层状和六方相。这些通过动态光散射、低温传输电子显微镜和小角 X 射线散射进行了表征。LSBDDS 在体外消化过程中药物的释放情况通常通过超速离心和形成的不同相中药物的定量来研究。此外，通过 X 射线粉末衍射和偏光显微镜对体外脂肪分解过程中沉淀的药物进行了表征。
