Development and Validation of a Gradient Elution High-Performance Liquid Chromatographic Method for Determination of Talinolol in Rat Plasma: Application to a Preclinical Food-Drug Interaction Study

A sensitive and reproducible high-performance liquid chromatographic (HPLC) method for determination of talinolol (TAL) in rat plasma was developed and validated using pindolol (PIN) as an internal standard. Both TAL and PIN were separated on a Zorbax Eclipse XDB C18 column by gradient elution with 0.1% aqueous formic acid and acetonitrile as the mobile phase. Detection was performed using fluorescence measurement at lambda(ex) 249 nm and lambda(em) 333 nm. The method was validated and found to be linear in the range of 10-2000 ng mL(-1). The limit of quantification was 10 ng mL(-1) based on 100 mu L of plasma. The variations for intra- and inter-day precision were less than 10%, and the accuracy values were between 92% and 102.9%. The extraction recoveries were more than 82%. The assay was successfully applied to an in-vivo pharmacokinetic study of TAL in rats that were administered a single oral dose of 10 mg kg(-1) TAL. The maximum concentration (C-max) and the area under the plasma concentration-time curve (AUC(0-12)) were 0.369 +/- 0.024 mu g mL(-1) and 1.429 +/- 0.027 mu g h mL(-1), respectively. The modulatory effect of apricot juice on P-glycoprotein-related efflux carriers was also investigated. Co-administration of apricot juice resulted in a significant increase of the amount of TAL in plasma (C-max and AUC(0-12) were 0.679 +/- 0.021 and 2.357 +/- 0.079, respectively; p < 0.05).