Laboratory of Pharmaceutical Engineering, Institute of Pharmacy, University of Bonn, Gerhard-Domagk-Str 3, 53121 Bonn, Germany.
Pharm Res. 2011 Mar;28(3):563-71. doi: 10.1007/s11095-010-0304-6. Epub 2010 Oct 29.
At laboratory scale, the most widely applied methods in therapeutic microencapsulation are based on emulsification using organic solvents. Here, glycofurol was proposed as non-toxic solvent to circumvent these inconveniences using a quasi-emulsion extraction method for the preparation of poly (lactide-co-glycolide) microspheres.
Matrix polymer and lipophilic drug were dissolved in glycofurol, building the internal phase, and emulsified under stirring into various external phases before microspheres could be obtained and characterized for their pharmacotechnical properties.
Microspheres were spherical with particle diameters around 100 to 200 μm and also showed a monomodal particle size distribution. The internal sponge-like structure was related to an incomplete glycofurol extraction (residual content: 16.9% ± 1.6% of total particle mass), which is, however, no toxicological drawback. The encapsulation rate of several model compounds increased with rising partition coefficient (Ibuprofen: 1.9% ± 0.6%, Ritonavir: 11.2% ± 0.4%, Lopinavir: 14.0% ± 2.2%, Sudan III: 28.3% ± 0.4%) due to the decreasing solubility in the external phase. In-vitro release kinetics were varying from a complete release after 4 h for Ritonavir to 3 weeks for Sudan III.
This new method was confirmed to be suitable for the preparation of microspheres with the use of a non-toxic solvent and to allow for the entrapment of lipophilic actives and their controlled release.
在实验室规模下，治疗性微囊化最广泛应用的方法基于使用有机溶剂的乳化作用。在这里，提议使用无毒溶剂甘油醛来规避这些不便，采用准乳液萃取法制备聚（乳酸-共-乙醇酸）微球。
基质聚合物和疏水性药物溶解在甘油醛中，形成内相，并在搅拌下乳化到各种外相中，然后得到微球，并对其药物技术性质进行了表征。
微球呈球形，粒径约为 100 至 200 μm，且具有单峰粒径分布。内部海绵状结构与不完全的甘油醛萃取有关（残留含量：占总粒子质量的 16.9%±1.6%），但这不是毒理学上的缺点。几种模型化合物的包封率随分配系数的升高而增加（布洛芬：1.9%±0.6%，利托那韦：11.2%±0.4%，洛匹那韦：14.0%±2.2%，苏丹红 III：28.3%±0.4%），这是由于在外部相中溶解度降低。体外释放动力学从利托那韦 4 小时完全释放到苏丹红 III 的 3 周不等。
该新方法被证实适用于使用无毒溶剂制备微球，并可包封疏水性活性物质及其控制释放。
