氯胺酮贴剂在大鼠体内的药动学考察

In vivo plasma pharmacokinetics of ketamine patch in rats

目的：建立测定大鼠血浆氯胺酮浓度的反相高效液相色谱外标法,考查氯胺酮贴剂在大鼠体内的血浆药动学。方法：24只SD大鼠随机分为4组,以氯胺酮注射液10 mg·kg^-1腹腔注射为对照组,以20,100,500 mg氯胺酮贴剂经皮给药为实验组。于不同时间点采血,血浆样品经处理后,采用RP-HPLC外标法测定大鼠血浆氯胺酮浓度,色谱柱为Syncronis C18柱（4.6mm×250 mm,5μm）,流动相为乙腈-甲醇-0.01%三乙胺（33∶45∶22）,流速为0.8 ml·min^-1,柱温25℃,检测波长220 nm。采用DAS软件计算药代参数。对各组药代参数MRT0-t、t1/2z、tmax、Cmax进行方差分析（α=0.05）。结果：RP-HPLC外标法氯胺酮最低检测限0.05μg·ml^-1,在0.1-20μg·ml^-1范围内,线性关系良好,Y=33.321X-0.467 3,R2=0.998 9,日内、日间RSD均小于10%。氯胺酮贴剂经皮给药20 mg最低检测限下未检出;100 mg、500 mg经皮给药组的MRT0-t、t1/2z、tmax较腹腔注射组延长,差异具有统计学意义（P〈0.05）,Cmax无显著统计学差异（P〉0.05）;500 mg剂量组MRT0-t、t1/2z、tmax、Cmax稍高于100 mg剂量组,差异具有统计学意义（P〈0.05）。结论：RP-HPLC外标法操作简便,准确可靠,适用于血浆氯胺酮浓度测定。氯胺酮贴剂经皮给药具有一定的缓释作用,增大贴剂含药量,可延长药物滞留时间及药物半衰期,提高血药峰浓度。该结果可为氯胺酮新剂型的研发及临床应用提供参考。

OBJECTIVE To establish an external standard reversed phase HPLC method for determination of rats＇ plasma concentration of ketamine,and to study the in vivo plasma pharmacokinetics of ketamine patch in rats.METHODS 24 SD rats were randomly divided into four groups.The rats given intraperitoneal injection of ketamine（10 mg·kg^-1） were selected as the control group,while the rats with percutaneous administration of ketamine patch（20 mg,100 mg and 500 mg） were as the experimental groups.Blood was sampled at different time points,and after treatment,the plasma samples were collected for determination of rat＇s serum ketamine concentration with external standard RP-HPLC（Syncronis C18column：4.6 mm × 250 mm,5 μm;mobile phase：acetonitrile-methanol-0.01% of triethylamine：33∶ 45∶ 22;flow rate：0.8 ml·min^-1;column temperature：25 ℃;detection wavelength：220 nm）.DAS was used to calculate pharmacokinetic parameters.Pharmacokinetic parameters including MRT0-t,t1 /2z,tmaxand Cmaxwere given variance analysis（α = 0.05）.RESULTS For external standard RP-HPLC to detect ketamine,the limit of detection（LOD） was 0.05 μg·ml^-1,the linear relationship was good（Y =33.321X-0.467 3,R2= 0.998 9） within the scope of 0.1-20 μg·ml^-1.RSD of intraday and inter-day assays were both less than 10%.The rats given percutaneous administration of ketamine patch（20 mg） was not detected under LOD;the rats with 100 mg and 500 mg percutaneous administration had longer MRT0-t,t1 /2zand tmax than the control group,with statistically significant difference（P〈0.05）;no statistically significant difference of Cmaxwas found（P〉0.05）;MRT0-t,t1 /2z,tmaxand Cmaxwere a bit higher in 500 mg group than 100 mg group,and the differences were statistically significant（P〈0.05）.CONCLUSION The method of external standard RP-HPLC is simple,accurate and reliable,which is suitable for determination of plasma ketamine concentration.Ketamine patch has certain slow-release effect.With the increase of the patch containing dosage,drug residence time and half-life time can be prolonged,and the blood peak concentration was improved.The results could be used to offer reference to research,development and clinical application of new dosage forms of ketamine.