title: Determination of free salicylic acid in chewing aspirin tablets by HPLC.
abstract: OBJECTIVE
  To establish a HPLC method for determining the content of free salicylic acid in chewing aspirin tablets.
  
  
  METHODS
  The determination was conducted on a HPLC column (C(18), 150 mm x 4.6 mm x 5 microm) with methanol-water-glacial acetic acid (8.0 5.5 1.0) as the mobile phase and the detection wavelength of 302 nm.
  
  
  RESULTS
  The calibration curve was linear within the concentration range of 2.65 to 31.77 microg/ml (r=0.999 97) of salicylic acid. The average recovery rate was 100.21% with relative standard deviation of 0.53% (n=6).
  
  
  CONCLUSIONS
  HPLC is quick and accurate of determining the content of free salicylic acid for chewing aspirin tablets.
authors.affiliation: Department of Pharmacy, General Navy Hospital of PLA, Beijing 100037, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Tian
authors.forename: Xin-shan
authors.initials: XS
authors.lastname: Chen
authors.forename: Rui-dong
authors.initials: RD
authors.lastname: Wang
mesh_terms: D001241:Aspirin / Q000008:administration & dosage / Q000032:analysis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D008409:Mastication; D020156:Salicylic Acid / Q000032:analysis*; D013607:Tablets
chemical_list: D013607:Tablets; D020156:Salicylic Acid; D001241:Aspirin