Investication And Application Of Quantitative Analytical Methods Of Fexofenadine And Pantoprazole In Human Plasma

Objectives: To develop two HPLC methods for the determination of fexofenadine andpantoprazole in human plasma, respectively.Methods: A high performance liquid chromatography method was developed to determine theconcentration of fexofenadine in human plasma. After a simple liquid-liquid extraction withacetyl acetate, the analyte and internal standard lorsatan were separated on a Diamonsil C₁₈column （150 min×4.6 mm, 5μm） and detected by fluorescence detector. The detection was set atthe excitation wavelength of 230 nm and the emission wavelength of 290 nm The mobile phasewas consisted of acetonitrile-water-phosphoric acid-triethylamine （32: 68: 0.8: 0.1, v/v/v/v）. Ahigh performance liquid chromatography method with UV detection was developed to determinethe concentration of pantoprazole in human plasma. After a simple liquid-liquid extraction withmixture of diethyl ether and acetyl acetate, the analyte and internal standard betamethason wereseparated on a Diamonsil C₁₈ column （200 mm×4.6 mm, 5μm）. The mobile phase was consistedof methanol-water （60: 40, v/v）.The detection was set at a wavelength of 288 nm.Results: The linear calibration curve of fexofenadine was obtained in the concentration range of0.01～1.0μg·mL^-1. The intra-and inter-day precision （RSD） was less than 9.6%, and the accuracywas within 100.9%. The main pharmacokinetic parameters after a single oral dose of threefexofenadine hydrochloride preparations 120 mg to 18 healthy volunteers were as following:C_max（0.50±0.23）, （0.49±0.24）, （0.50±0.22）μg·mL^-1, T_max（1.53±0.32）, （1.50±0.30）, （1.47±0.32） h,AUC_0-t（3.31+1.66）, （3.19±1.45）, （3.36±1.71）μg·h·mL^-1, AUC_0-∞（3.58±1.68）, （3.47±1.46）, （3.63±1.71）μg·h-mL^-1, t_1/2（15.55±4.36）, （15.64±4.73）, （16.02±4.80） h, respectively. The linearcalibration curve of pantoprazole was obtained in the concentration range of 0.02～5.0μg·mL^-1.The intra-and inter-day precision （RSD） was less than 8.4%, and the accuracy was within104.3%. The main pharmacokinetic parameters after a single oral dose of two pantoprazolepreparations 40 nag to 20 healthy volunteers were as following: C_max （3.68±1.01）, （3.40±1.15）μg·mL^-1, T_max （3.00±0.40）, （3.00±0.46） h, AUC_0-t （8.14±5.06）, （8.39±5.47）μg·h·mL^-1, AUC_0-∞（8.29±5.09）, （8.62±5.61）μg·h·mL^-1, t_1/2（1.61±0.28）, （1.85±0.27） h. Conclusions: The two methods can be utilized for bioequivalence study of fexofenadine andpantoprazole preparations, respectively, which provide the advantage of simplicity, speed andsensitivity.