| 1 Objective It is clinically proven that using Kangai injection and docetaxel injection together shows better outcomes than using docetaxel injection individually,and also reduces the side effects of docetaxel.However,the pharmacokinetic study of the two drugs is less,more is the synergistic effect of the two drugs.In vivo,pharmacokinetics are closely related to pharmacodynamics,and the changes of clinical efficacy may be related to the changes of pharmacokinetics of two drugs.Therefore,this research explores the two drugs used from the following aspects: whether the interaction leads to the change of pharmacological behavior,and then influence docetaxel pharmacokinetic parameters:(1)to establish a method for biological samples determination of high sensitivity,pave the way for the determination of docetaxel in vivo;(2)To investigate the effects of single administration of Kangai injection on the pharmacokinetic parameters of docetaxel in rats;(3)To investigate the effects of multiple administration of Kangai injection on pharmacokinetic parameters of docetaxel in rats.2 Methods(1)establishing the high performance liquid chromatography method of docetaxel in the plasma samples of rats: detect docetaxel concentrations in plasma using high-performance liquid chromatography and validate the selected methods using methodology(specificity,sensitivity,precision,accuracy,rate of extraction and stability).(2)pharmacokinetic studies of Kangai injection and docetaxel injection in rat:single dose and multiple dosing methods.There are 24 SD rats,each of which contains 12 female rats and 12 male rats.Three of them are experimental groups,which is separately injected high dose group of Kangai injection(5.4m L/kg),middle dose group of Kangai injection(3.6m L/kg),low dose group of Kangai injection(1.8m L/kg).The fourth group of them(the blank group)is injected the same volume of normal saline instead of Kangai injection.Each group of six is injected docetaxel injection 15mg/kg.Experimental groupof the single dose is injected the high,middle and low doses of Kangai injection through the veins in tail in the morning and then is continually injected the docetaxel injection in5 mins.The blank group is injected normal saline through the veins in tail for 5 mins and then is injected the same volume of docetaxel injection.Experimental group of the multiple doses is injected high dose of Kangai injection,middle dose of Kangai injection,low dose of Kangai injection through the veins in tail for 9 days,the blank group is injected the same volume of normal saline for 9 days.In the tenth day,the three experimental groups is separately injected the corresponding dose Kangai injection,the blank group is injected the corresponding dose saline and then are all continually injected the docetaxel injection in 5 mins.The four groups are all conducted blood collection from the eye inferiorly venous after injection of 3min,5min,10 min,15min,30 min,60min,120 min,240min,360 min and 480 min.The HPLC method was used to determine the area of docetaxel and paclitaxel in rats and bring the area ratio to the standard curve to calculate the blood drug concentration.Docetaxel's pharmacokinetic parameters were calculated through DAS2.0 software.Through the comparison of pharmacokinetic parameters between experimental groups and the blank group with the help of IBM SPSS Statistics 21 software,it is used to evaluate the effects of Kangai injection on docetaxel.3 Results(1)The linear regression equation of docetaxel is y=0.2293x-0.0272 in plasma of rats.It shows good linear relationship when the concentration of docetaxel ranging in0.1~30?g/m L.The correlation coefficient(r2)is 0.9992,the quantitative limit LLOQ is0.10?g/m L,and the precision RSD(day and daylight)< 15%(n=5);Relative recovery >85%(n=5);Docetaxel and Standard paclitaxel solution In the-20?refrigerator placed 30 days stable(RE:-5.77%~1.92%);Docetaxel plasma sample place 6h before treatment and place 6h at indoor temperature after dispose stability(RE:-5.77%~1.44%);Repeated freezing and thawing 3 times(RE:-7.69%~7.69%);Long term frozen 7 days,14 days are stable(RE:-11.53%~5.77%).(2)pharmacokinetic studies of Kangai injection and docetaxel injection in rat:respectively to investigate the pharmacokinetic parameters ofthe compartmental model(t1/2? ?t1/2??t1/2? ?V1? CL ?AUC(0-t)?AUC(0--?))and pharmacokinetic parameters of non compartmental models(AUC0-t?AUC0--??MRT0-t?MRT0--??t1/2z?CLz?Cmax?Vz).Results show:(1)single dose of drugs:The parameters of compartmental model showed that the elimination half-life t1/2? of high dose group,middle dose group,low dose group and blank control group were respectively:66.22±6.93(min)?69.32±0(min)?49.23±17.24(min)?67.67±3.67(min).After analysis,only low dose group of t1/2? was significantly less than the blank control group,the difference was statistically significant.There was no significant difference in the parameters of non compartmental model.(2)Multiple doses of drugs:The parameters of compartmental model showed that the elimination half-life t1/2? of high dose group,middle dose group,low dose group and blank control group were respectively:56.93±18.89(min)?52.01±16.32(min)?66.32±6.70(min)?69.32±0(min).The area under the curve AUC(0-t)respectively:111.86±22.22(mg/L*min)?132.80±26.51(mg/L*min)?120.11±4.90(mg/L*min)?104.20±22.66(mg/L*min).After analysis,only the middle dose group of t1/2? and AUC(0-t)was statistically significant compared with blank group.The statistical parameters of the non compartmental model showed that the area under the curve AUC0-t of the high dose group,the middle dose group,the low dose group and the blank control group were respectively:103.83±20.37(mg/L*min)? 124.059±25.04(mg/L*min)? 109.832±4.72(mg/L*min)?95.54±21.14(mg/L*min);The average residence time MRT(0-?)of drug in vivo were respectively:36.56±11.61(min)? 36.75±8.36(min)? 39.188±11.85(min)?52.52±10.40(min);The elimination half-life t1/2z was respectively: 33.02±14.20(min)?28.664±5.23(min)? 36.88±17.66(min)? 51.96±7.53(min);The apparent distribution volume Vz was respectively:6.22±1.62(L/kg)? 4.87±0.61(L/kg)? 6.60±2.86(L/kg)?10.55±2.85(L/kg).The pharmacological parameters MRT0-? ? t1/2z and Vz of the middle-dose group and high-dose group were significantly lower than those in the blank control group(P<0.05).In the low dose group,only Vz was lower than that in the blank group(P<0.05).Juding form the concentration-time curve,compared to the controlgroup,the combination therapy group had increased docetaxel AUC(0-t)in rats,but except the AUC(0-t)of middle dose group has increased significantly(P<0.05),the other groups have no statistically significance.4 Conclusion The built HPLC method is fast,accurate,more specific,and relative higher sensitive,which is used for the research in docetaxel and the interaction between docetaxel and other drugs.In the case of a single dose of kangai,it shows that after low doses of Kangai injection in rats,it has accelerated the elimination of docetaxel in rats,but middle and high doses have no effect.In the case of a multiple-dose of kangai injection,Low dose Kangai injection had an effect on the appearance of the surface distribution of docetaxel in rats;The middle dose group and high dose group of Kang'ai injection injections accelerated the metabolism and elimination of docetaxel in rats,which also affected the volume of surface distribution of docetaxel in the rats. |
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