益康唑固体脂质纳米粒滴眼液兔眼单次点眼的眼部药代动力学研究

Ocular pharmacokinetics of econazole solid lipid nanoparticle eye drops after single dose topical administration in rabbits

目的观察益康唑固体脂质纳米粒(E-SLNs)滴眼液在兔眼单次点眼后的眼部药代动力学。方法采用微乳法制备质量分数0.2%的E-SLNs,采用微量稀释法评估其在体外抑制镰刀菌的最小抑菌浓度(MIC)并与那他霉素滴眼液进行比较。取健康无眼疾新西兰大白兔25只,任取4只作为空白对照组,未给予药物干预;采用随机数字表法将另21只实验免依据处理时间点不同随机分为7个组,每组3只。双眼均用E-SLNs滴眼液点眼,分别于点眼后不同时间点采用滤纸收集泪液,处死动物后剖取角膜,采用高效液相色谱分析法测定泪液和角膜样品中的药物含量,并对样品药物的精密度、回收率、稳定性及药物抑菌能力进行评估。结果泪液及角膜样品药物精密度的相对标准偏差(RSD)为2.34%~4.04%;稳定性分析结果显示,各样品中药物RSD均小于10%。E-SLNs的半数抑菌浓度(MIC 50)和90%抑菌浓度(MIC 90)分别为0.37μg/ml和0.89μg/ml,那他霉素滴眼液的MIC 50和MIC 90分别为1.15μg/ml和1.70μg/ml。E-SLNs滴眼液兔眼单次点眼后,泪液、角膜中的药物质量分数达峰时间均为5 min,峰值质量分数分别为597.64μg/g和33.15μg/g。结论E-SLNs滴眼液兔眼单次点眼后在泪液及角膜中可获得远高于对致病镰刀菌MIC的药物质量浓度。

Objective To investigate the pharmacokinetics of econazole solid lipid nanoparticles(E-SLNs)after administration of one single dose in rabbit eyes.Methods E-SLNs with 0.2%econazole was prepared by microemulsion method.Its antifungal activity against Fusarium isolated from the eyes of patients with fungal keratitis was evaluated in vitro and was compared with natamycin eye drops.Four healthy New Zealand white rabbits were assigned to the blank control group without any drug interference during the experimental period,and other matched 21 rabbits were randomized into 7 groups according to the specimen-collected time,with 3 rabbits in each group.E-SLNs of 50μl was singly applied to conjunctival sac in both eyes in the 21 rabbits,and tear was collected using a filter paper at 5,15,30,60,90,120 and 180 minutes following administration of the drug.The cornea specimen was collected at above-mentioned time points respectively.The drug levels in each sample were assayed by high performance liquid chromatography.The accuracy,recovery rate,stability and antifungal activity of the drugs in tear fluid and cornea were detected.This study protocol was approved by the Life Science Ethics Review Committee of Henan Eye Hospital(No.HENNCA-2017-22).Results For the tear samples and corneal tissue samples,the relative standard deviation(RSD)of the accuracy of the drug was 2.34%-4.04%;the stability analysis result showed that the RSD of the drugs was less than 10%.The 50%minimum inhibitory concentration(MIC 50)and 90%minimum inhibit concentration(MIC 90)of E-SLNs were 0.37μg/ml and 0.89μg/ml,respectively.The MIC 50 and MIC 90 of natamycin were 1.15μg/ml and 1.70μg/ml,respectively.After one single dose application of E-SLNs eye drops,the peak time of the drug in tears fluids and cornea of rabbits were 5 minutes and maximum concentrations in tears and cornea were 597.64μg/g and 33.15μg/g,respectively.Conclusions The drug levels in tears and cornea achieved are higher than MIC against Fusarium.