Study On The Dissolution Rate Of Four Preparations Of Ginkgo Biloba Extract And The Pharmacokinetics Of Beagle Dogs And Their Correlation In Vitro And In Vivo

Ginkgo probably originated about 200 million years ago.Its leaves have been identified as a valuable medicinal supplement for mankind since more than 2000 years.Ginkgo biloba L.extract and its preparations have many beneficial effects in senile dementia,memory loss and cerebrovascular and brain diseases.This study was to compare the release rate in Vitro and the pharmacokinetic characteristics of four different Ginkgo leaf preparations(YIKANGNINGTM tablets,GINATONTM tablets,AOSHITM dripping pills,YINXINKETM dispersible tablets).To established the correlation between absorption rate in vivo and release rate in vitro of lactones ingredients of four different Ginkgo leaf preparations.Details are as follows:1 Review of the related literaturesThis paper summarizes the chemical constituents,pharmacological effects of ginkgo leaves and the development of ginkgo biloba extract and its preparations,including in vitro dissolution and pharmacokinetic research and the evaluation method between absorption rate in vivo and release rate in vitro.2 Studies on in Vitro Release Rate of four different Ginkgo leaf preparationsA ultra-high performance liquid tandem mass spectrometry(UPLC-MS/MS)method for simultaneous determination of four compositions Bilobalide,Ginkgolides A,B,C in dissolution medium of the four different Ginkgo leaf preparations has been established and its application to the study on in vitro release rate the preparationsAS YINXINKE for reference preparation,the f1,f2 factors method were used to evaluation of differences in release between two of the four preparations.Results:The factor f1 and f2 of bilobalide is 9.15 and 59.14 respectively between YINXINKE and AOSHI.There are differences in release between two of the four preparations(f2<50).3 To establish a sensitive UPLC-ESI-MS/MS method for the simultaneous determination of kaempferol(KMF),quercetin(QCT),isorhamnetin(ISR),ginkgolides A(GA),ginkgolides B(GB),ginkgolides C(GC),and bilobalide(BB)in plasmaA UPLC-MS/MS method with short analysis time(4.0 min)for simultaneous determination of seven compositions in beagle dog plasma has been described for the first time.The method is simple,rapid and accurate.4 The pharmacokinetic study after beagle dog oral administration of four Ginkgo leaf productsThe pharmacokinetic parameters were calculated with DAS 3.20.The relative bioavailability(Fr)was calculated when taking GINATON as reference product.The comparative bioavailability was assessed by calculating individual AUC0-t(the area under the concentration-time curve from time-zero to the last measurable concentration),Cmax(the maximum observed concentration),and Tmax(the time to Cmax)values of these seven analytes of four Ginkgo leaf preparations.The pharmacokinetic parameters were conducted using SPSS 17.0.The results suggest that dispersible tablets compared with traditional tablet can increase absorption and bioavailability of flavonoids,especially for QCT(P<0.05),but it has adverse action for lactones ingredients.Besides,the Tmax of dropping pill AOSHI was found to be significantly lower among the four preparations.It told us that different flavonoids and lactones ingredients were influenced differently by the differences in preparations,which was possible because of their difference chemical structure.5 in vitro-in vivo corelationsThe Deconvolution method was used to the correlation between absorption rate in vivo and release rate in vitro of lactones ingredients of four different Ginkgo leaf preparations.Obvious correlation was observed between absorption rate in vivo and release rate in vitro of lactones ingredients(ginkgolides A,ginkgolides B,ginkgolides C)of four different Ginkgo leaf preparations.