Simultaneous Determination of Metformin, Nateglinide and Gliclazide in Pharmaceutical Preparations Using Micellar Liquid Chromatography

A micellar chromatographic method has been developed and validated for simultaneous separation and determination of metformin(MF), nateglinide (NT) and gliclazide (GL). The separation was carried out using a Nucleosil C18 column, 150 mm × 4.6 mm i.d., 5 μm particle size, using micellar mobile phase consisting of sodium dodecyl sulphate (SDS), n-propanol with UV detection. The optimum conditions for the simultaneous separation of the three drugs were 0.12 M SDS, 10% (v/v) n-popanol, 0.3% triethylamine adjusted to pH5.6 with a flow rate of 1 ml.min(-1) and detection at 254 nm. The limit of detection (LOD) of MF, NT, GL were 0.047, 0.00115, 0.036 μg.mL(-1) respectively. The method showed good linearity in the ranges of 0.4-16 μg.mL(-1), (r(2)=0.999), 0.8-16 μg.ml(-1) (r(2)=0.999) and 1-40 μg.ml(-1) (r(2)=0.999) for MF, NT, GL respectively. The suggested method was successfully applied for the analysis of the three antidiabetic drugs in pharmaceutical preparations with average recoveries of 99.66%, 100.08% and 100.31% for MT, NT and GL respectively. The results obtained were in good agreement with those obtained from comparison methods. The method was validated regarding accuracy and precision.