pH梯度法结合逆向蒸发法制备硫酸多黏菌素E脂质体

Preparation of colistin sulphate liposomes by pH-gradient method coupled with reverse evaporation technique

目的制备硫酸多黏菌素E脂质体，并对其处方工艺进行研究。方法采用pH梯度法和pH梯度法结合逆向蒸发法制备硫酸多黏菌素E脂质体，用超滤法分离游离药物与脂质体，用HPLC法测定包封率，考察各处方及工艺因素对包封率的影响。结果硫酸多黏菌素E脂质体最佳处方和工艺：磷脂和胆固醇质量比为3：1，药物与磷脂质量比为1：20，pH值梯度范围为3．0—5．8,50℃孵育20min，包封率达70％以上。结论采用pH梯度法结合逆向蒸发法制备的硫酸多黏菌素E脂质体具有较高的包封率。

Objective To prepare colistin sulphate liposomes and study on preparation processes. Methods Colistin sulphate liposomes were encapsulated into the liposomes using active loading that pH gradient method, pH gradient method coupled with reverse evaporation technique, free colistin sulphate and liposomes were separated by ultrafiltration. HPLC was applied to determine the entrapment efficiency（EE）. The influence of various factors on EE were investigated. Results The optimum formula and preparation conditions were m （phospholipid） ： m （cholesterol） = 3： 1, m （drug） ： m （ lipid ） = 1 ： 20, pH gradient ranged from 3.0 to 5.8, liposomes incubated at 50 ~C for 20 min. The entrapment efficiency of colistin sulphate in liposomes was above 70%. Conclusions The liposomes are prepared with good encapsulation efficiency by pH-gradient method coupled with reverse evaporation technique.