抑菌型除虫菊酯微胶囊的制备及性能

Preparation and Characterization of Antibacterial Natural Pyrethrin Microcapsules

摘要:

为了提高天然除虫菊酯的抑菌性，采用复凝聚法，以大豆分离蛋白和水杨酸为壁材制备天然除虫菊酯微胶囊。以微胶囊的包封率和载药率为评价标准，设计单因素和正交实验确定反应的最佳条件，对微胶囊的形态、结构、热稳定性、缓释性、储存稳定性和抑菌性进行表征。结果表明，大豆分离蛋白?水杨酸微胶囊制备的最佳条件为pH值4.25、壁材质量分数2.0%、芯壁质量比0.5、大豆分离蛋白和水杨酸质量比2∶1。包封率可达30.6%，载药率最大可达3.51%，平均粒径为38.3 μm。微胶囊表面呈球状、完整无裂痕，FT?IR分析结果表明除虫菊酯成功包埋，200 ℃内微胶囊的热稳定性与缓释性良好，保留了水杨酸对大肠杆菌和金黄色葡萄球菌良好的抑菌性，对白色念珠菌无抑菌性。微胶囊在低温避光条件下的储存稳定性一般，货架期应设为3个月。

Abstract:

In order to enhance the antibacterial properties of natural pyrethrins， a type of natural pyrethrin microcapsules was prepared using soy protein isolate（SPI） and salicylic acid（SA） as wall materials by complex coagulation method. Single-factor and orthogonal experiments were employed to optimize preparation conditions of pyrethrin microcapsules based on embedding rate and drug loading. The morphology， structure， thermal stability， slow-release capability， storage stability and antibacterial activity were characterized. The results indicate that the optimal conditions are pH 4.25， wall material concentration 2.0%， core-wall ratio 0.5， and SPI/SA mass ratio 2∶1. Under these conditions， the microcapsule exhibits an encapsulation efficiency of approximately 30.6%， a maximum drug loading capacity of 3.51%， and an average particle size of 38.3 μm. The microcapsule is spherical and complete， with a crack-free surface. FT-IR analysis confirms the successful embedding of pyrethroid components. Furthermore， the microcapsule demonstrates good thermal stability and sustained release performance at temperatures below 200 ℃. The effective antibacterial properties of salicylic acid against Escherichia coli and Staphylococcus aureus are retained but no antibacterial activity against Candida albicans. The storage stability of microcapsules under low-temperature and dark conditions is moderate， and a recommended shelf life of 3 months is suggested.