TMC60包衣的维生素A阳离子脂质体眼球滞留性及刺激性研究

目的以维生素A棕榈酸酯（VAP）为主药,制备N-三甲基壳聚糖（TMC）包衣的阳离子脂质体,对其角膜滞留性及刺激性进行研究。方法采用薄膜分散法制备TMC60（季胺化程度为60%）包衣的VAP脂质体（VAPL）,即TMC-VAPL;采用悬挂泡技术和束缚泡技术进行离体眼球表面接触角及解吸附动力学研究;Draize评分法结合组织学检查,评价其对兔角膜的刺激性。结果 VAPL粒径分布均匀,TMC60包衣后荷正电性;与未包衣的VAPL相比,TMC-VAPL在角膜表面接触角明显降低,解吸时间明显延长;对兔角膜无刺激性。结论 TMC-VAPL具有阳离子脂质体的优势,可延长角膜滞留时间,并具有良好的生物相容性,值得进一步研究。

Study on corneal retention and irritation behavior of vitamin A-loaded cationic liposomes

Objective To prepare vitamin A palmitate（VAP）-loaded cationic liposomes with N-trimethyl chitosan（TMC）-coating,and investigate their corneal retention and irritation behavior.Methods Vitamin A palmitate（VAP）-loaded liposomes（VAPL） were prepared by the film dispersion method followed with TMC60-coating（quaternization degree of 60%） to obtain TMC60-coated VAPL.The contact angle and corneal retention behavior were evaluated by sessile bubble technique and captive bubble technique.Ocular irritation test was carried out based on the Draize method and histological examination.Result VAPL was uniformly distributed with positive surface charge after TMC60-coating and it exhibited smaller contact angle and longer corneal retention time with little corneal irritation after TMC60-coating.Conclusion TMC60-coated VAPL has advantages of cationic liposomes in extending the corneal retention time with promising biocompatibility,which deserves further study.