A validated HPLC method with ultraviolet detection for the determination of buformin in plasma

Abstract

A sensitive and rapid high-performance liquid chromatographic assay is developed and validated for the determination of buformin in plasma. After addition of metformin as the internal standard, the analytes were deproteinated with acetonitrile, washed with dichloromethane, and the resulting supernatant injected. Chromatography was performed at ambient temperature by pumping a mobile phase of 0.03 m diammonium hydrogen phosphate buffer (pH 7, 250 mL) in methanol (750 mL) at a fl ow rate of 1 mL/min through a silica column. Buformin and metformin were detected at 236 nm, and eluted 9.8 and 15.4 min, respectively. No endogenous substances were found to interfere. Calibration curves were linear over the concentration range of 20-2000 ng/mL. The limit of quantitation was 20 ng/mL. The intra- and inter-day relative standard deviation (RSD) was 8.3%, or less, and the accuracy was within 10.1% of the relative error (RE). The method is suitable in pharmacokinetic investigation of buformin.

Determination of lamotrigine in small volumes of plasma by high-performance liquid chromatography

“…Silica column with aqueous-organic mobile phases were increasingly used in the analysis of polar ionic compounds, because such applications can provide better retention, sensitivity and versatility than those with reversed-phase columns [26]. Previously we have used silica columns with aqueous-organic mobile phases to quantitate plasma concentrations of several basic drugs, such as buformin, metformin and mitoguazone [27][28][29]. These compounds all have a guanidine group and show some structure similarity with lamotrigine.…”