Development, Validation and Application of HPLC Method for Metformin in Rabbit Plasma

Objective: This study was aimed at conducting a pharmacokinetic evaluation of metformin in rabbit plasma samples using rapid and sensitive HPLC method and UV detection. Methods: Acetonitrile was used for protein precipitation in the preparation of plasma samples. Reverse phase chromatography technique with silica gel column (250 mm x 4.6 mm, 5 μm) at 30°was used for the separation purpose. Methanol and phosphate buffer (pH 3.2) mixture was used as a mobile phase with flow rate 0.8 ml/min. The wavelength of UV detector was adjusted at 240 nm. Results: The calibration curve was linear in a range of 0.1-1 μg/ml with R² = 0.9982. The precision (RSD, %) values were less than 2%, whereas, accuracy of method was higher than 92.37 %. The percentage recovery values ranged between 90.14 % and 94.97 %. LOD and LOQ values were 25 ng/ml and 60 ng/ml, respectively. Cmax and AUC0-t values were found to be 1154.67 ± 243.37 ng/ml and 7281.83 ± 210.84 ng/ml.h, respectively after treating rabbits with a formulation containing 250 mg metformin. Conclusion: Based on the above findings, it can be concluded that present method is simple, precise, rapid, accurate and specific and thus, can be efficiently used for the pharmacokinetic study of metformin.