A simple and rapid high-performance liquid chromatography method for determination of alendronate sodium in beagle dog plasma with application to preclinical pharmacokinetic study.

A simple and rapid high performance liquid chromatographic (HPLC) method for quantifying alendronate in beagle dog plasma was developed, validated and applied to a pharmacokinetic study. The sample preparation involved coprecipitation with CaCl(2) and derivatization with o-phthalaldehyde. Chromatographic separation was achieved on a Diamonsil C(18 )(250 x 4.6 mm, 5 microm) using acetonitrile-0.4% EDTA-Na(2) (16:84, v/v) containing 0.034% of NaOH as mobile phase. The fluorimetric detector was operated at 339 nm (excitation) and 447 nm (emission). The linearity over the concentration range of 5.00-600 ng/mL for alendronate was obtained and the lower limit of quantification was 5.00 ng/mL. For each level of quality control samples, inter-day and intra-day precisions were less than 8.52 and 7.42% and accuracies were less than 9.07%. The assay was applied to the analysis of samples from a pharmacokinetic study. Following the oral administration of 70 mg alendronate sodium to beagle dogs, the maximum plasma concentration (C(max)) and elimination half-life were 152 +/- 27.3 and 1.75 +/- 0.267 h, respectively. The method was demonstrated to be highly feasible and reproducible for pharmacokinetic studies.