title: Development and validation of a UPLC method for the determination of duloxetine hydrochloride residues on pharmaceutical manufacturing equipment surfaces.
abstract: BACKGROUND
  In pharmaceutical industries, it is very important to remove drug residues from the equipment and areas used. The cleaning procedure must be validated, so special attention must be devoted to the methods used for analysis of trace amounts of drugs. A rapid, sensitive, and specific reverse phase ultra-performance liquid chromatographic (UPLC) method was developed for the quantitative determination of duloxetine in cleaning validation swab samples.
  
  
  METHODS
  The method was validated using an Acquity UPLC™ HSS T3 (100 × 2.1 mm(2)) 1.8 μm column with a isocratic mobile phase containing a mixture of 0.01 M potassium dihydrogen orthophosphate, pH adjusted to 3.0 with orthophosphoric acid and acetonitrile (60:40 v/v). The flow rate of the mobile phase was 0.4 ml/min with a column temperature of 40°C and detection wavelength at 230 nm. Cotton swabs, moisten with extraction solution (90% methanol and 10% water), were used to remove any residue of drug from stainless steel, glass and silica surfaces, and give recoveries >80% at four concentration levels.
  
  
  RESULTS
  The precision of the results, reported as the relative standard deviation, were below 1.5%. The calibration curve was linear over a concentration range from 0.02 to 5.0 μg/ml with a correlation coefficient of 0.999. The detection limit and quantitation limit were 0.006 and 0.02 μg/ml, respectively. The method was validated over a concentration range of 0.05-5.0 μg/ml.
  
  
  CONCLUSIONS
  The developed method was validated with respect to specificity, linearity, limit of detection and quantification, accuracy, precision, and robustness.
authors.affiliation: Dr. Reddy's Laboratories Ltd., Analytical R & D, IPDO, Bachupally, Hyderabad, Andhra Pradesh, India ; Department of Chemistry, S.A.S., V.I.T. University, Vellore, Tamilnadu, India.
authors.forename: Navneet
authors.initials: N
authors.lastname: Kumar
authors.forename: D
authors.initials: D
authors.lastname: Sangeetha
authors.forename: P
authors.initials: P
authors.lastname: Balakrishna
keywords: Cleaning validation; UPLC-UV; duloxetine; residues; swab analysis