Jelvehgari M, Siahi-Shadbad M R, Azarmi S, Martin Gary P, Nokhodchi Ali
School of Pharmacy, Tabriz University of Medical Sciences, Tabriz 51664, Iran.
Int J Pharm. 2006 Feb 3;308(1-2):124-32. doi: 10.1016/j.ijpharm.2005.11.001. Epub 2005 Dec 15.
Benzoyl peroxide (BPO) is commonly used in topical formulations for the treatment of acne and athletes foot. Skin irritation is a common side effect, and it has been shown that controlled release of BPO from a delivery system to the skin could reduce the side effect while reducing percutaneous absorption. Therefore, the aim of the present study was to produce ethylcellulose microparticles containing BPO which were able to control the release of BPO to the skin. In order to optimize the microparticle formulation, factors affecting the physical properties of microparticles were also investigated. Benzoyl peroxide microparticles were prepared using an emulsion solvent diffusion method by adding an organic internal phase containing benzoyl peroxide, ethyl cellulose and dichloromethane into a stirred aqueous phase containing polyvinyl alcohol. Drug content, particle size analysis and loading yield were determined in the prepared microparticles. BPO microparticles were then incorporated into standard vehicles for release studies. Scanning electron microscopy was used to study the shape and morphology of the microsponges. The micrograph of microsponges showed that they were spherical in shape and contained pores. These pores resulted from the diffusion of solvent from the surface of the microparticles and thus the particles were designated as microsponges. It was shown that the drug:polymer ratio, stirring rate, volume of dispersed phase influenced the particle size and drug release behavior of the formed microsponges and that the presence of emulsifier was essential for microsponge formation. The results showed that, generally, an increase in the ratio of drug:polymer resulted in a reduction in the release rate of BPO from microsponges which was attributed to a decreased internal porosity of the microsponges.
过氧化苯甲酰（BPO）常用于局部制剂中治疗痤疮和足癣。皮肤刺激是常见的副作用，并且已经表明，从给药系统向皮肤控释BPO可以减少副作用，同时减少经皮吸收。因此，本研究的目的是制备含有BPO的乙基纤维素微粒，其能够控制BPO向皮肤的释放。为了优化微粒制剂，还研究了影响微粒物理性质的因素。通过将含有过氧化苯甲酰、乙基纤维素和二氯甲烷的有机内相加入到含有聚乙烯醇的搅拌水相中，使用乳液溶剂扩散法制备过氧化苯甲酰微粒。测定所制备微粒中的药物含量、粒度分析和载药量。然后将BPO微粒掺入标准载体中进行释放研究。使用扫描电子显微镜研究微海绵的形状和形态。微海绵的显微照片显示它们呈球形且含有孔隙。这些孔隙是由溶剂从微粒表面扩散形成的，因此这些颗粒被称为微海绵。结果表明，药物与聚合物的比例、搅拌速率、分散相体积影响所形成微海绵的粒径和药物释放行为，并且乳化剂的存在对于微海绵的形成至关重要。结果表明，一般来说药物与聚合物比例的增加导致BPO从微海绵中的释放速率降低，这归因于微海绵内部孔隙率的降低。
