Simultaneous determination of nine constituents by validated UFLC-MS/MS in the plasma of cough variant asthma rats and its application to pharmacokinetic study after oral administration of Huanglong cough oral liquid

•Huanglong cough oral liquid (HL) was treated for pediatric cough variant asthma.•UFLC-MS/MS method was established and validated for determining nine constituents.•The pharmacokinetic studies were performed on cough variant asthma model rats.•This research could lay a good foundation to reveal the metabolism of HL in vivo.