1%毛果芸香碱脂质体滴眼剂在兔眼房水中的药代动力学

Evaluation of Ocular Pharmacokinetics for 1% Pilocarpine liposome Using the Rabbit Eye Model with RP-HPLC

目的对1%毛果芸香碱滴眼剂的两种不同剂型:1%毛果芸香碱水溶液和1%毛果芸香碱脂质体在兔眼房水中的药代动力学进行对比研究。方法 RP-HPLC 法采用 ODS—C_(18)柱,流动相:0.5%三乙胺的 KH_2PO_4(10 mmol/L)缓冲液(pH2.5)-乙腈(98:2,v/v);流速:1.0 ml/min,检测波长:215 nm;60只兔随机分为实验组和对照组,每组30只兔(60只眼),分别给实验组和对照组兔眼结膜囊滴入1%毛果芸香碱脂质体和1%毛果芸香碱水溶液各50μl,并于给药后5、10、30、40、60、90、120、180、240及360 min 时抽取3只兔(6眼)房水,用二氯甲烷提取房水中药物,用 RP-HPLC 法测定房水中的药物浓度。结果 RP-HPLC 法可以用于眼房水中毛果芸香碱的含量测定,毛果芸香碱浓度在0.1～20μg/ml 范围内线性良好,提取回收率68.10±1.9%。两种不同剂型毛果芸香碱滴眼后,不同时间点1%脂质体的房水药物浓度明显高于1%水溶液滴眼液的房水浓度(P=0.000～0.002),前者的药时曲线下面积是溶液的2.86倍,且1%脂质体滴眼剂在用药后6h 房水中仍可测出毛果芸香碱。结论毛果芸香碱脂质体可以明显提高毛果芸香碱的生物利用度,从而可能增强疗效,减少用药频率,值得进一步研究开发。

Objective To compare the ocular pharmacokinetics for two formulations of pilocarpine in the aqueous humor of rabbit eyes with RP-HPLC method.Methods The RP-HPLC mothed was performed on a column of ODS-C_(18) with the mobile phase consisting of 0.5% of tri- ethylamine(TEA)of phosphate solutions(10 mmol·l^(-1),pH2.5)and acetonitrile(98:2 v/v).The detection wavelength was 215 nm.60 rab- bits were divided into 2 groups randomly,each group received 50 μL of 1% generic pilocarpine,1% liposome pilocarpine.Aqueous humor was withdrawn from 3 rabbits(6 eyes)respectively at 5,10,30,40,60,90,120,180,240 and 360 min after instillation.Pilocarpine was extracted from aqueous humor with dichloromethane.The drug was analyzed by reversed phase high pressure liquid chromatography (RP-HPLC).Results The linear calibration curve was obtained in the concentration range of 0.1～20 μg·ml^(-1).The average recovery was 68.10%±1.9%.The pilocarpine Liposome gave higher aqueous humor concentration of drug than generic pilocarpine at all time periods(P= 0.000～0.002).The areas under curve of liposome were 2.86 times as much as that of drops.Measurable amounts of drug following 1% lipo- some were still observed at 360 min,while drug levels at 180 min following 1% drop therapy were nil.Conclusion Our study results demonstrat- ed that pilocarpine liposome significantly increases ocular bioavailability.It shows that pilocarpine liposome might prolong the drug activity,de- crease frequent administration.