肉桂醛微乳的制备及其抑菌活性研究

目的制备肉桂醛微乳并考察其溶解量、稳定性和抑菌活性。方法采用相转化法初步筛选出可行的表面活性剂,再采用伪三元相图法选择最佳的表面活性剂并制样,用UV法测定肉桂醛最大溶解量。用透射电子显微镜观察其形态,纳米粒度分析仪测量其粒径及分布。在不同处理条件下观察变化以评价其稳定性。通过测定其对不同细菌及真菌的最小抑菌浓度(MIC)评价其抑菌活性。结果制备出澄清透明的肉桂醛微乳,最佳表面活性剂是聚氧乙烯氢化蓖麻油-40(RH40);肉桂醛的最大溶解量是(98.88±0.31)mg/mL;肉桂醛微乳的稳定性良好,在本实验的处理条件下均保持澄清透明;肉桂醛微乳对所选细菌的MIC集中在125μg/mL,对所选真菌的MIC介于16～62μg/mL。结论制备的肉桂醛微乳具有较大的载药量、良好的稳定性和较好抑菌效果,达到预期目标。

Studies on cinnamaldehyde microemulsion preparation and its antibacterial activity

Objective To develop cinnamaldehyde microemulsion(CME),study its stability and antibacterial activity,and determine the dissolved amount of cinnamaldehyde in the CME as well.Methods The phase inversion method was applied to selecting the feasible surfactants preliminarily,then the pseudoternary phase diagram method was adopted to choose the optimal surfactant,and the maximum absorption of cinnamaldehyde in CME samples was measured by ultraviolet spectrophotometry.The shape of CME was observed by transmission electron microscope(TEM),and the average size and distribution of CME were examined by nanoparticle size analyzer.The stability of CME was evaluated in different conditions.The antibacterial and antifungal activities were determined by measuring the minimum inhibitory concentration(MIC) on different species of pathogenic bacteria and fungi,respectively.Results A clear and transparent formulation of CME was developed.RH40 was the optimal surfactant for CME that could contain the maximum cinnamaldehyde at(98.88 ± 0.31) mg/mL.The CME had an excellent stability as it could always keep clear under all the test conditions.The MICs of the CME on bacteria were mainly at 125 μg/mL,while MICs of the CME on fungi were between 16 and 62 μg/mL.Conclusion The CME has a relatively high contentofcinnamaldehydewithexcellent stability andantimicrobialactivity,which implies that this study has basically achieved the desired goal.