title: Development and validation of stability indicating the RP-HPLC method for the estimation of related compounds of guaifenesin in pharmaceutical dosage forms.
abstract: OBJECTIVE
  A stability-indicating gradient reverse phase liquid chromatographic (RP-LC) method was developed for the quantitative determination of related substances of guaifenesin in pharmaceutical formulations.
  
  
  METHODS
  The baseline separation for guaifenesin and all impurities was achieved by utilizing a Water Symmetry C18 (150 mm × 4.6 mm) 5 μm column particle size and a gradient elution method. The mobile phase A contains a mixture of 0.02 M KH2PO4 (pH 3.2) and methanol in the ratio of 90:10 v/v, while the mobile phase B contains 0.02 M KH2PO4 (pH 3.2) and methanol in the ratio of 10:90 v/v, respectively. The flow rate of the mobile phase was 0.8 ml/min with a column temperature of 25°C and detection wavelength at 273 nm.
  
  
  RESULTS
  Guaifenesin was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal, and photolytic degradation.
  
  
  CONCLUSIONS
  The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection and quantification, accuracy, precision, and robustness.
authors.affiliation: Dr. Reddy's Laboratories Ltd., Analytical R and D, IPDO, Bachupally, Hyderabad, India ; Department of Chemistry, S. K. University, Anantapur, Andhra Pradesh, India.
authors.forename: Sunil Pingili
authors.initials: SP
authors.lastname: Reddy
authors.forename: K Sudhakar
authors.initials: KS
authors.lastname: Babu
authors.forename: Navneet
authors.initials: N
authors.lastname: Kumar
authors.forename: Y V V Sasi
authors.initials: YV
authors.lastname: Sekhar
keywords: Development; HPLC; degradation; guaifenesin; impurity; stability-indicating; validation