HM30181A,a potent P-glycoprotein inhibitor,potentiates the absorption and in vivo antitumor efficacy of paclitaxel in an orthotopic brain tumor model

摘要

Objective:Delivery of chemotherapeutic drugs to the brain has remained a major obstacle in the treatment of glioma,owing to the presence of the blood-brain barrier and the activity of P-gp,which pumps its substrate back into the systemic circulation.The aim of the present study was to develop an intravenous formulation of HM30181 A(HM)to inhibit P-gp in the brain to effectively deliver paclitaxel(PTX)for the treatment of malignant glioma.Methods:Two formulations of solubilized HM were designed on the basis of different solid dispersion strategies:i)spray-drying[polyvinlypyrrolidone(PVP)-HM]and ii)solvent evaporation[HP-β-cyclodextrin(cyclodextrin)-HM].The P-gp inhibition of these 2 formulations was assessed on the basis of rhodamine 123 uptake in cancer cells.Blood and brain pharmacokinetic parameters were also determined,and the antitumor effect of cyclodextrin-HM with PTX was evaluated in an orthotopic glioma xenograft mouse model.Results:Although both PVP-HM and cyclodextrin-HM formulations showed promising P-gp inhibition activity in vitro,cyclodextrin-HM had a higher maximum tolerated dose in mice than did PVP-HM.Pharmacokinetic study of cyclodextrin-HM revealed a plasma concentration plateau at 20 mg/kg,and the mice began to lose weight at doses above this level.Cyclodextrin-HM(10 mg/kg)administered with PTX at 10 mg/kg showed optimal antitumor activity in a mouse model,according to both tumor volume measurement and survival time(P<0.05).Conclusions:In a mouse orthotopic brain tumor model,the intravenous co-administration of cyclodextrin-HM with PTX showed potent antitumor effects and therefore may have potential for glioma therapy in humans.