Laboratory of Pharmaceutical Engineering, Institute of Pharmacy, University of Bonn, Germany.
Eur J Pharm Biopharm. 2012 May;81(1):57-63. doi: 10.1016/j.ejpb.2012.01.009. Epub 2012 Jan 28.
The aim of the present study was to compare different commercial available types of Poly(d,l-lactide-co-glycolide) (PLGA), multiblock copolymers of PLGA and polyethylene gylcol (PEG) as well as blends of PLGA and PEG regarding the preparation of microparticles and the release behavior of encapsulated protein. Microspheres were prepared by the solvent evaporation technique using the same conditions for each formulation. The encapsulation rate of bovine serum albumin (BSA) was unaffected by the different polymer types, and the mean was 79±4%. Microspheres composed of blends of PLGA and PEG showed a porous structure, a higher specific surface area, an inhomogenous distribution of protein and a higher release rate of BSA than microspheres consisting of PLGA, whereas the release profiles were the same. The specific surface area of microparticle formulations composed of diblock copolymers was the highest with 8.57±0.07m(2)/g emphasized by a highly porous, sponge-like structure. The triblock copolymer formulation revealed nearly spherical particles with a slightly uneven surface. Although the triblock copolymer consists of 10% PEG, the specific surface area was the lowest of all formulations. The rapid hydration due to PEG leads to a swollen matrix, which released the protein in a slow and continuous way.
本研究的目的是比较不同市售的聚（丙交酯-共-乙交酯）（PLGA）、PLGA 和聚乙二醇（PEG）的多嵌段共聚物以及 PLGA 和 PEG 的共混物在制备微球和包封蛋白释放行为方面的差异。采用相同的条件，通过溶剂蒸发技术制备微球。牛血清白蛋白（BSA）的包封率不受不同聚合物类型的影响，平均值为 79±4%。由 PLGA 和 PEG 共混物组成的微球具有多孔结构、更高的比表面积、蛋白分布不均匀和更高的 BSA 释放率，而释放曲线相同。由二嵌段共聚物组成的微球制剂的比表面积最高，为 8.57±0.07m(2)/g，具有高度多孔、海绵状结构。三嵌段共聚物制剂呈现出近球形颗粒，表面略有不均匀。尽管三嵌段共聚物含有 10%的 PEG，但比表面积是所有制剂中最低的。由于 PEG 的快速水合作用导致基质肿胀，以缓慢连续的方式释放蛋白。
