Effect of the microencapsulation of nanoparticles on the reduction of burst release
Effect of the microencapsulation of nanoparticles on the reduction of burst release
复制标题
DOI：
10.1016/j.ijpharm.2007.05.066
复制
发表时间：
2007-11-01
影响因子：
5.8
通讯作者：
Ubrich, N.
中科院分区：
文献类型：
--
作者：
Hasan, A. Sheikh;Socha, M.;Ubrich, N.
控释制剂包括载药微粒和纳米粒，特别是低分子药物，其初期控释是主要问题之一。本工作的目的是通过W/O/NV乳液，通过使用非水溶性聚合物和适当的有机溶剂将聚合物纳米粒子包覆到聚合物微粒子中，以制备这些复合微粒子。对其进行了体外表征(包封率、平均粒径和释放动力学)，并与相同方法制备的纳米粒和经典微球进行了比较。用溶解于二氯甲烷的聚己内酯(PCL)制备纳米粒子，用乙基纤维素和Eudradit RS溶解于聚己内酯的非溶剂乙酸乙酯制备微球。分别选择布洛芬和醋酸曲普瑞林作为亲脂模型药物和亲水模型药物。布洛芬的包封率较高，而醋酸曲普瑞林的包封率较低，主要是由聚己内酯和Eudradit RS单独使用或与乙基纤维素混合制成的制剂。复合微粒的突破性显著降低，这可能是由于药物在纳米微粒基质形成的双层聚合物壁上扩散较慢，随后又一步扩散到微粒聚合物壁上。(C)2007 Elsevier B.V.保留所有权利。
The initial burst release is one of the major problems in the development of controlled release formulations including drug-loaded micro-and nanoparticles, especially with low molecular weight drugs. The objective of the present work was to encapsulate, by the W/O/NV emulsion, polymeric nanoparticles into polymeric microparticles by using non-water soluble polymers and appropriate organic solvents for the preparation of these composite microparticles. They were characterized in vitro (encapsulation efficiency, mean diameter and release kinetics) and compared with nanoparticles and classical microparticles prepared by the same method. Poly-e-caprolactone (PCL) dissolved in methylene chloride was used to make nanoparticles, whereas ethylcellulose and Eudragit RS dissolved in ethyl acetate, a non-solvent of poly-epsilon-caprolactone, were used for the preparation of microparticles. Ibuprofen and triptorelin acetate were chosen as lipophilic and hydrophilic model drugs, respectively. High entrapment efficiencies were obtained with ibuprofen whereas lower amounts of triptorelin acetate were encapsulated, mainly with formulations prepared with poly-epsilon-caprolactone and Eudragit RS used alone or blended with ethylcellulose. The burst was significantly lower with composite microparticles and may be explained by the slower diffusion of the drugs through the double polymeric wall formed by the nanoparticle matrix followed by another diffusion step through the microparticle polymeric wall. (C) 2007 Elsevier B.V. All rights reserved.