title: Validated spectrophotometric methods for the simultaneous determination of telmisartan and atorvastatin in bulk and tablets.
abstract: OBJECTIVE
  Three simple, accurate, and reproducible spectrophotometric methods have been developed and validated for simultaneous estimation of telmisartan (TELM) atorvastatin (ATV) in combined tablet dosage form.
  
  
  METHODS
  The first method is based on first-order derivative spectroscopy. The sampling wavelengths were 223 nm (zero crossing of TELM) where ATV showed considerable absorbance and 272 nm (zero crossing of ATV) where TELM showed considerable absorbance. The second method Q-analysis (absorbance ratio), involves formation of Q-absorbance equation using respective absorptivity values at 280.9 nm (isobestic point) and 296.0 nm (λmax of TELM). The third method involves determination using multicomponent mode method; sampling wavelengths selected were 296.0 and 246.9 nm.
  
  
  RESULTS
  TELM and ATV followed linearity in the concentration range of 5-40 and 4-32 μg/ml for method I, 5-30 μg/ml and 2-24 μg/ml for method II and III, respectively. Mean recoveries for all three methods were found satisfactory. All methods were validated according to International Conference on Harmonization Q2B guidelines.
  
  
  CONCLUSIONS
  The developed methods are simple, precise, rugged, and economical. The utility of methods has been demonstrated by analysis of commercially available tablet dosage form.
authors.affiliation: Department of Pharmaceutical Chemistry, S.R.M. College of Pharmacy, S.R.M. University, Kattankulathur, Kancheepuram (Dt), Tamil Nadu, India.
authors.forename: Kaliappan
authors.initials: K
authors.lastname: Ilango
authors.forename: Pushpangadhan S Shiji
authors.initials: PS
authors.lastname: Kumar
keywords: Absorbance ratio; atorvastatin; derivative spectroscopy; multicomponent analysis; telmisartan