[关键词]
[摘要]
目的建立盐酸青藤碱(sinomenine hydrochloride,SM-HCl)脂质体包封率的测定方法,并阐明药物在脂质体中的滞留特性。方法采用薄膜分散法制备SM-HCl脂质体。以HPLC法测定脂质体药物的量,色谱柱为Kromasil ODS C18柱(250 mm×4.6 mm,5μm),流动相为甲醇-水-乙二胺(55∶45∶0.225),体积流量1.0 mL/min,检测波长265 nm。以离心沉淀-离心超滤法测定SM-HCl脂质体的包封率,并与以枸橼酸缓冲液(pH 7.0)水化的脂质体样品稀释前后的包封率进行对比。结果辅料与溶剂对青藤碱的定量测定无干扰,青藤碱在9.82~78.56μg/mL线性关系良好(r=0.999 7),平均回收率在99.29%~100.8%,日内与日间精密度良好(RSD≤2.1%)。50μL药液可使超滤膜对药物的吸附达到饱和。以枸橼酸缓冲液(pH 7.0)水化的脂质体样品的包封率为33.16%,稀释1倍后该样品的包封率降至14.75%。结论 HPLC法与离心沉淀-离心超滤法结合可用于测定SM-HCl脂质体的包封率,该方法快速、准确;离心超滤中应弃去50μL初滤液以确保滤液与脂质体外水相药物浓度一致;青藤碱与脂质双分子层有一定的亲和力,但在脂质体中的滞留性较差。
[Key word]
[Abstract]
To develop a method for determining the entrapment efficiency of sinomenine hydrochloride (SM-HCl) liposomes and to illuminate the drug retention property in the liposomes. Methods Thin film hydration method was employed to prepare SM-HCl liposomes. HPLC was used to determine drug content of the liposomes. A Kromasil ODS C18 column (250 mm × 4.6 mm, 5 μm) was used with an isocratic elution composed of methanol, water, and ethylenediamine in the ratio of 55 : 45 : 0.225 at a flow rate of 1.0 mL/min. The column was maintained at 30 ℃. The UV detector was set at 265 nm. Centrifugation sedimentation combined with centrifugation ultrafiltration was used to determine drug entrapment efficiency of the liposomes. The entrapment efficiencies of an SM-HCl liposome sample (hydrated with citric buffer solution at pH 7.0) and its diluted sample were compared. Results The pharmaceutical excipients and solvents for analysis had no interference with the determination of sinomenine. Sinomenine had a good linear relation in the range of 9.82—78.6 μg/mL (r =0.9997), the intra-day and inter-day precisions were with RSD≤2.1% and the averaged recovery was within 99.29%—100.8%. SM-HCl solution (50 μL) was able to saturate the drug absorption of ultrafiltration films. The entrapment efficiencies of the SM-HCl liposome sample (hydrated with citric buffer solution at pH 7.0) and its double-volume diluted sample were 33.16% and 14.75%, respectively. Conclusion HPLC and centrifugation sedimentation combined with centrifugation ultrafiltration are able to determine the entrapment efficiency of SM-HCl liposomes efficiently and accurately. Initial filtrate (50 μL) should be discarded in the process of ultrafiltration in order that the drug concentration in filtrate may be equal to that of external aqueous phase of liposomes. The retention of sinominine in the liposomes is poor, although it has considerable affinity to the lipid bilayers.
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[基金项目]
上海市教委重点学科资助项目(J50302);上海中医药大学课程建设项目(实验教学组)