In-vivo studies of metformin modified release formulations

Abstract

The current study was undertaken to conduct in vivo studies and to establish the new validated bioanalysis for the determination of Metformin present in Blood Plasma by using the Reverse Mode-LC Method. The separation of the Metformin was carried out on Reverse mode LC using Shimadzu® LC - 10AT with the following Stationary Phase: Kromasil octadecyl silane column (25 cm x 4.6 mm i.d.,  5µm) Eluent: Cyanomethane: 25 mM Pentane Sulfonic acid of pH 3.5. ratio 09:91 % v/v with 1.0 ml/min flow rate has been fixed, and this has been measured at 232 nm, and the sample volume will be 10 ul using Rheodyne 7725i injector. Based on the method established for Metformin, the drug peak is well resolved at 11.11 min and validated as per US FDA guidelines with respect to linearity, accuracy, precision, robustness ruggedness, and stability. The calibration curve was found to be linear over a range of 0.025 –1 μg/mL (r² = 0.9999). The method has proved high sensitivity and specificity.  Established method have been used to quantify the Pharmacokinetic parameters like Cmax, Tmax, AUC⁰_-t & AUC_0-∞, Keli, and t_1/2  studied and the values for reference formulation (660.05±91.52 ng/ml, 4.46 ±1.10  h, 8280.41 ± 1356.39 g.h/ml, 9200.31± 1569.26 ng.h/ml, 0.11±0.03 h^-1, and 6.96±1.53 h respectively) and the test formulation ( 705.06±102.58 ng/ml, 4.13±0.74 h, 8185.21±2101.56 g.h/ml, 8946.39± 2457.66 ng.h/ml, 0.12±0.03 h^-1, and 6.06±1.61 h, respectively) were compared and found to be biologically equivalent. Based on the Pharmacokinetic and statistical analysis Test formulation of Metformin Hydrochloride containing 500 mg Metformin Hydrochloride (modified release formulations) is biologically equivalent to that of the Reference.