title: Development and validation of the liquid chromatographic method for simultaneous estimation of metformin, pioglitazone, and glimepiride in pharmaceutical dosage forms.
abstract: BACKGROUND
  A simple, precise, and accurate HPLC method for simultaneous estimation of metformin hydrochloride (MET), pioglitazone hydrochloride (PIO), and glimepiride (GLIMP) was developed and validated.
  
  
  METHODS
  Chromatographic separation of the drugs was performed by using a Phenomenex-ODS-3 (C-18) column (250 × 4.60 mm, 5 μm) with a mobile phase consisting of methanol:acetonitrile:15 mM potassium dihydrogen phosphate (pH 4) in the proportion of 40:35:25 (v/v) at a flow rate of 1 ml/min. Detection was carried out using a UV-SPD-10AVP detector at 240 nm.
  
  
  RESULTS
  The retention time for MET, PIO, and GLIMP were 2.85 ± 0.03 min, 4.52 ± 0.03 min, and 7.08 ± 0.02min, respectively. Parameters such as linearity (0.2-50 μg/ ml for MET, 0.2-30 μg/ml for PIO, and GLIMP, respectively), precision (intra-day % RSD was 1.01-3.24 and inter-day % RSD was 1.54-4.09 for MET; intra-day % RSD was 1.03-2.09 and inter-day % RSD was 2.26-3.10 for PIO; and intra-day% RSD was 1.00-3.15 and inter-day % RSD was 1.58-3.07 for GLIMP), accuracy (99.66 ± 0.14 for MET, 98.46 ± 0.40 for PIO, and 98.62 ± 0.39 for GLIMP), specificity and robustness were calculated in accordance with ICH guidelines.
  
  
  CONCLUSIONS
  The method was proved to be simple, rapid, precise, accurate, and cost effective.
authors.affiliation: Department of Pharmaceutics, Al-Ameen College of Pharmacy, Bangalore, Karnataka, India.
authors.forename: Vinay
authors.initials: V
authors.lastname: Pandit
authors.forename: Roopa S
authors.initials: RS
authors.lastname: Pai
authors.forename: Kshama
authors.initials: K
authors.lastname: Devi
authors.forename: Gurinder
authors.initials: G
authors.lastname: Singh
authors.forename: Satya
authors.initials: S
authors.lastname: Narayana
authors.forename: Sarasija
authors.initials: S
authors.lastname: Suresh
keywords: Glimepiride; ICH guidelines; metformin hydrochloride; pioglitazone hydrochloride; simultaneous