地塞米松脂肪乳滴眼液载药性能的评价

Drug-loading performance evaluation of dexamethasone eye drops with lipid emulsion as carrier

目的:建立测定以脂肪乳为载体地塞米松滴眼液中药物在各相中的分布和包封率方法,并分析其作为载药性能评价指标的可行性。方法:根据脂质乳中相密度差异,在8℃、30 000 r·min^(-1)离心力下分离在油、水及油水界面相中的药物;依据凝胶分子筛原理对脂质乳滴表面的游离药物和包封于乳滴中的药物进行柱分离;色谱条件:采用Sun Fire C_(18)色谱柱(250 mm×4.6 mm,5μm),以乙腈-水(28∶72)为流动相,流速1.0 m L·min^(-1),检测波长240 nm,柱温30℃,进样量20μL。结果:水相、油相、油水界面磷脂层中地塞米松的占比为42.43%、31.12%、24.45%,体系中地塞米松的包封率为50.11%。结论:相分布和包封率指标合用能准确评价脂肪乳的载药性能,所建立的方法可作为以脂肪乳为载体滴眼液的质量控制的手段之一。

Objective： To establish methods for distribution and encapsulation efficiency of dexamethasone in eye drops with lipid emulsion as carrier in different phases, and to analyze the feasibility of this method used in drug performance evaluation. Methods： Based on the differences of density in each phase of lipid emulsion, centrifuge with 8 ℃, 30 000 r· min-1 was used to separate the drug in oil, in water and in oil/water interface phase. The free drug on the surface and drugs coated in the emulsion droplet were separated and determined by micro column centrifugation using gel molecular sieve method. A Sun Fire C18 column （ 250 mmx 4.6 ram, 5 μm ） was adopted, the mobile phase was acetonitrile-water （ 28 ： 72 ） at the flow rate of 1.0 mL· min-1, the detection wavelengthwas 240 nm, the column temperature was 30 ℃, and the sample volume was 20 μL. Results： The distribution of dexamethasone in water phase, oil phase and lecithin layer at oil/water interface were 42.43%, 31.12% and 24.45%, respectively. The encapsulation efficiency of dexamethasone in emulsion droplet was 50. 11%. Conclusion： The phase distribution and entrapment efficiency can accurately evaluate the performance of drug- loading in eye drops with lipid emulsion as carrier, and the established method can be used for quality control.