RP-HPLC Method Developed for the Determination of Metformin in Human Saliva

Several extraction steps involved while analyzing metformin in plasma necessitates the need to develop a simple less tedious RP-HPLC method for analysis human saliva.Blank saliva (2 mL) was spiked with 2 mL solution (12.5 µg mL-1) of and 1 (0.5 caffeine as internal standard (IS). The mixture vortex mixed centrifuged at 3000 rpm 10 minutes. A portion resultant injected into HPLC machine (Agilent 1260 infinity). optimized conditions included mobile phase methanol:water (80:20 v/v) containing 0.1 % orthophosphoric acid, isocratic elusion mode, an injection volume µL, flow rate mLmin-1, 35°C detection wavelength 232nm. Calibration curve(1.25to25.0 prepared by plotting peak height ratios Vs IS against their corresponding concentrations. validated according ICH guidelines. Metformin eluted 1.6 2.6 minutes respectively. precise (<1 RSD), accurate (% Er 1.00 recovery 99.98 %) linear calibration curve (r= 0.9987). developed can be used determination saliva. Keywords: Metformin, Saliva, Isocratic elution,