Abstract:Objective To develop a pre-column derivatization HPLC/FLD method for determining the content of cyclovirobuxine D (CB) in rat plasma, and to evaluate the pharmacokinetics of cyclovirobuxine D phospholipid complex (CBPC) and CB in SD rats by oral administration. Methods The solvent evaporation method was used to prepare CBPC. The preparation protocol was optimized by central composite design, with the ratio of phospholipid and CB, concentration of principal agent as the independent variables, and with the compound rate as the response variable. Twelve male rats were evenly randomized into two groups with each containing 6 animals. Rats were orally given CBPC and CB (60 mg/kg, with CB count). Blood samples were collected from the retinal venous plexus of SD rats after oral administration of CBPC and CB at 15 min, 30 min, 1, 2, 3, 4, 5, 6, 8, 12 and 24 h time points, and the blood concentrations of CB was determined by HPLC/FLD. The HPLC method employed the C18 column (250 mm × 4.6 mm,5 μm) with a mobile phase of methanol-water (85∶15) at a flow rate of 1.0 mL·min-1. The excitation wavelength was set at 231 nm, emission at wavelength 385 nm, and the column temperature was 25℃. Results The pharmacokinetic parameters of CBPC and CB were calculated as follows: AUC0-t(1 703.81±549.38) μg·h·L-1 and (619.93±75.67) μg·h·L-1, Tmax (6.00±0) h and (4.33±0) h, Cmax(82.32±9.55) μg·L-1 and (69.27±8.66) μg·L-1. The relative bioavailability of CBPC was 274.84%. Conclusion Phospholipid complex can improve the oral bioavailability of CB in rats.