Transdermal Diffusion Of Ginkolide B Flexible Liposome

Ginkgolides is the main active ingredients of Ginkgo biloba leaf extracts,and have a significant effect in heart and cerebral vessels,nervous system and senile dementia. Especially,Ginkolide B (GB) is the most powerful and to treat vascular dementia(VD). As one kind of new drug carrier,liposomes is one kind of new dosage form belonging to target-oriented drug delivery system,and it can improve pharmacokinetics characteristics. Therefore,we prepared GB flexible liposome in order to enhance brain activity.A method was developed for the determination of GB concentration in liposomes and entrapment efficiency and biological samples by HPLC,it was proved that this method was accurate,sensitive,specific and good enough to be used in pharmacokinetic study of GB. We had applied film dispersion method to prepare GB flexible liposome. Through orthogonal experimental design,one optimum recipes and prepare craft of GB flexible liposome was founded.Through the transmission electron microscopy,the form of liposome was observed,with Zetasizer 3000HSA laser particle size analytica linstrument,the particle size and zeta potential of the particles was measured. The stability of GB flexbile liposome was valuated with the acid value and peroxide value in 4,25,40℃for 60 days.The results showed that liposome was intact spherical, average encapsulation efficiency was 75.91%,the mean particle diameter was 208.3nm,and Zeta potential was-49.2mV.The GB flexible liposome was stored in 4℃would keep stability.GB permeation tests in vitro through the skin of rats were performedin modified Franz diffusion cells. To compare the accumulated permeation amount and the transdermal permeability of alcoholic solution of GB,flexible liposome of GB and ordinaryliposomes of GB.The result showed that flexible liposome can significantly enhance the diffusion rate of GB through the skin of rats (P＜0.01)The pharmacokinetic parameters of GB flexible liposome were studied after peroral administration and cutaneous penetration on dazhui of governor vessel. The experimental results showed that acupucture point cutaneous penetration in brain woule enhance AUC and Cmax in brain.The AUC of acupucture point cutaneous penetration is 1.24 times of peroral administration. And it had better brain targeting than peroral administration (P<0.05).