Rosenblatt Karin M, Douroumis Dionysios, Bunjes Heike
Department of Pharmaceutical Technology, Institute of Pharmacy, Friedrich-Schiller-University Jena, Lessingstrasse 8, 07743 Jena, Germany.
J Pharm Sci. 2007 Jun;96(6):1564-75. doi: 10.1002/jps.20808.
Aqueous colloidal monoolein/poloxamer dispersions are under investigation as drug delivery systems. Depending on the composition and preparation procedure these dispersions may either contain predominantly vesicular particles or nanoparticles of cubic inner structure. To study the influence of ultrastructure on drug release, corresponding dispersions loaded with the model drugs diazepam (two different concentrations) and chloramphenicol were prepared by high-pressure homogenization with or without subsequent heat treatment. The dispersions were characterized with regard to particle size and their ultrastructure was confirmed with small angle X-ray diffractometry. Two techniques with high time resolution, differential pulse polarography (DPP) and ultrafiltration at low pressure were compared for their suitability to monitor rapid release from the dispersions. Instantaneous release was found for both drugs independent on the type of particle structure with the amount of released drug being controlled by the partition coefficient. Both release methods were suitable to monitor the rapid appearance of the releasable drug in the release medium.
水胶体单油酸甘油酯/泊洛沙姆分散体作为药物递送系统正在研究中。根据组成和制备程序，这些分散体可能主要包含囊泡颗粒或具有立方内部结构的纳米颗粒。为了研究超微结构对药物释放的影响，通过高压均质化制备了负载有模型药物地西泮（两种不同浓度）和氯霉素的相应分散体，有或没有随后的热处理。对分散体进行粒度表征，并用小角X射线衍射法确认其超微结构。比较了两种具有高时间分辨率的技术，差分脉冲极谱法（DPP）和低压超滤法监测分散体快速释放的适用性。发现两种药物的瞬时释放均与颗粒结构类型无关，释放药物的量由分配系数控制。两种释放方法均适用于监测释放介质中可释放药物的快速出现。
