Development of two step liquid–liquid extraction tandem UHPLC–MS/MS method for the simultaneous determination of Ginkgo flavonoids, terpene lactones and nimodipine in rat plasma: Application to the pharmacokinetic study of the combination of Ginkgo biloba dispersible tablets and Nimodipine tablets

•Simultaneous quantitation of seven active compounds of GBE and nimodipine in rat plasma after combination administration.•Compare the pharmacokinetic behaviors of combined group and single group after oral administration.•Provide that the combination administration is convenient as well as efficient for clinical applications.