Holgado M A, Arias J L, Cózar M J, Alvarez-Fuentes J, Gañán-Calvo A M, Fernández-Arévalo M
Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Sevilla, c/Profesor García González 2, Seville, Spain.
Int J Pharm. 2008 Jun 24;358(1-2):27-35. doi: 10.1016/j.ijpharm.2008.02.012. Epub 2008 Feb 17.
In the present work, two methods for the preparation of lidocaine-loaded PLGA microparticles are compared. The differences between the polymeric particles obtained by solvent evaporation (SEVM) or flow focusing (FF) were studied by means of scanning electron microscopy and surface thermodynamics determinations. A detailed investigation of the capabilities of the polymer particles to load this drug is described. The physical state of the drug in the polymeric particles and the existence of interactions between both entities were studied by differential scanning calorimetry. The main factors determining the lidocaine incorporation and the release kinetics were the synthesis procedure followed, the amount of drug dissolved in the organic phase during the synthesis routine, the type of polymer (molecular weight and end chemical groups) and the size and the hydrophobic/hydrophilic properties of the particles. The FF technology allowed higher drug incorporations and slower release kinetics. The release studies showed a biphasic profile probably due to diffusion-cum-degradation mediated processes.
在本研究中，比较了两种制备载利多卡因聚乳酸-羟基乙酸共聚物（PLGA）微粒的方法。通过扫描电子显微镜和表面热力学测定研究了通过溶剂蒸发法（SEVM）或流动聚焦法（FF）获得的聚合物微粒之间的差异。描述了对聚合物微粒载药能力的详细研究。通过差示扫描量热法研究了聚合物微粒中药物的物理状态以及两者之间相互作用的存在情况。决定利多卡因包封率和释放动力学的主要因素包括所采用的合成程序、合成过程中溶解在有机相中的药物量、聚合物类型（分子量和端基化学基团）以及微粒的大小和疏水/亲水性质。流动聚焦技术允许更高的药物包封率和更慢的释放动力学。释放研究显示出双相特征，这可能是由于扩散-降解介导的过程。
