Rapid RP-HPLC Method for Simultaneous Estimation of Some Antidiabetics; Metformin, Gliclazide and Glimepiride in Tablets.

An isocratic RP-HPLC method has been developed for rapid and simultaneous separation and estimation of three antidiabetics drugs, metformin, gliclazide and glimepiride in tablet dosage forms within 6 minutes. Separation was carried out on a Thermo Scientific® BDS Hypersil C8 column (5µm, 2.50 x 4.60 mm) using a mobile phase of MeOH : 0.025M KH2PO4 adjusted to pH 3.20 using ortho - phosphoric acid (70 : 30, v/v) at ambient temperature. The flow rate was 1 mL/min and UV detection was set at 235 nm. The retention time of metformin, gliclazide and glimepiride was noted to be 3.06, 4.33 and 6.00 minutes respectively, indicating a very short analysis time rather than other reported methods. Also, limits of detection were reported to be 0.05, 1.21 and 0.11 µg/mL for metformin, gliclazide and glimepiride, respectively, showing a high degree of the method sensitivity. The method was then validated according to ICH guidelines where it was found to be accurate, reproducible and robust. Finally, the method was compared statistically with reference methods indicating that there is no significant difference between them in respect of precision and accuracy.