title: RP-HPLC method for simultaneous estimation of tenofovir disoproxil fumarate, lamivudine, and efavirenz in combined tablet dosage form.
abstract: BACKGROUND
  A simple, precise, accurate, and rapid reverse phase-high performance liquid chromatography (RP-HPLC) method with UV-Visible detector has been developed and subsequently validated for the simultaneous determination of tenofovir disoproxil fumarate (TDF), lamivudine (LAMI), and efavirenz (EFV) in their combined tablet dosage form.
  
  
  METHODS
  The separation was based on the use of a Kromasil C18 analytical column (150 × 4.6 mm, i.d., 5 μm). The mobile phase consisted of a mixture of 70 volumes of methanol and 30 volumes of 10 mM phosphate buffer (pH 5.0). The separation was carried out at 40°C temperature with a flow rate of 1 ml/min.
  
  
  RESULTS
  Quantitation was achieved with UV detection at 254 nm, with linear calibration curves at concentration ranges of 1-6 μg/ml for TDF and LAMI and 2-12 μg/ml for EFV. The recoveries obtained were 99.46-101.36% for LAMI, 99.57-101.42% for TDF, and 99.96-100.87 for EFV.
  
  
  CONCLUSIONS
  The method was validated according to International conference of harmonisation guidelines in terms of accuracy, precision, specificity, robustness, limits of detection and quantitation, and other aspects of analytical validation.
authors.affiliation: Department of Quality Assurance, Shri Sarvajanik Pharmacy College, Mehsana, Gujarat, India.
authors.forename: Dhara S
authors.initials: DS
authors.lastname: Bhavsar
authors.forename: Bhavini N
authors.initials: BN
authors.lastname: Patel
authors.forename: Chhaganbhai N
authors.initials: CN
authors.lastname: Patel
keywords: Efavirenz; RP-HPLC; lamivudine; tenofovir disoproxil fumarate; validation