利多卡因微乳的制备及电镜观察

目的考察构成利多卡因微乳各组分的比例并进行制备。方法绘制伪三元相图考察不同Km(表面活性剂／助表面活性剂)值对利多卡因微乳区形成的影响,根据微乳区面积大小选择制备利多卡因微乳的最佳Km值,测定利多卡因微乳的粒径大小及粒径分布范围,测定利多卡因微乳的理化特性,对利多卡因微乳的形态及体系类型进行电镜观察。结果当Km=3时伪三元相图形成的微乳区面积最大,利多卡因微乳平均粒径为(29．8±14．4)nm,其中98％的粒径范围位于15．1-45．5 nm之间．2％的粒径范围位于77．9-261．3 nm之间;25℃恒温下利多卡因微乳的粘度为25 mPa·S,电导率为130 μs／cm,折光率为1．473,利多卡因微乳为水包油(O／W)型微乳,利多卡因微乳体系为大小不均的球形多分散体系。结论通过伪三元相图法可以得到理想的利多卡因微乳各组分比例范围,马尔文粒径测定结合透射电镜分析对观察并测定微乳的粒径、分布、形态及体系类型效果较理想。

Preparation and electron microscopic observation of lidocaine microemulsion

OBJECTIVE: To prepare and determine the proportion of the components of lidocaine microemulsion. METHODS: Pseudoternary phase diagrams of the prepared lidocaine microemulsion with different Km (surfactant/cosurfactant) were generated to determine the optimal Km according to the size of the microemulsion area. The diameter and its distribution range, viscosity, electric conductivity and refractivity of lidocaine microemulsion drop was determined, and the appearance and system type of the microemulsion was observed using electron microscope. RESULTS; Maximum microemulsion area in the pseudoternary phase diagrams was obtained with the Km of 3, and the drop size of the microemulsion averaged 29.8+/-14.4 nm (with up to 98% of the drop size ranging between 15.1-45.5 nm and 2% between 77.9-261.3 nm). At 25 degrees C, the viscosity, electric conductivity and refractivity of the microemulsion was 25 mPa.S, 130 micros/cm and 1.473, respectively, and the lidocaine microemulsion was identified to belong to O/W type. The microemulsion drop appeared in spherical shape of heterogeneous sizes in a multi-disperse system. CONCLUSION: The optimal proportion of the components in lidocaine microemulsion can be obtained by analyzing pseudoternary phase diagrams, and the drop size, distribution, shape and system type can be determined or observed through Maerwen Zetasizer combined with electron microscopic observation.