Determination of cimetidine in human plasma by high-performance liquid chromatography following liquid-liquid extraction

J Chromatogr B Biomed Appl. 1995 Jun 9;668(1):117-23. doi: 10.1016/0378-4347(95)00055-n.


A new method is described for the determination of cimetidine in human plasma. The drug and internal standard (ranitidine) were separated on a Nucleosil C18 5 microns (25 x 4.6 mm I.D.) column using a mobile phase of acetonitrile-phosphate buffer, pH 6.2 (25:75, v/v) containing 2.5 g/l heptane sulphonic acid. The mobile phase was delivered at a flow-rate of 0.9 ml/min, detection was by ultraviolet absorption at 228 nm and concentrations were calculated on the basis of peak areas. The drugs were extracted from alkaline plasma into ethyl acetate using a salting out procedure which involved the addition of 100 ml of a saturated solution of K2CO3 to each 250-microliters plasma aliquot. The method was validated over the concentration ranges 50-3000 ng/ml and 100-7000 ng/ml for two separate studies. Mean coefficients of variation were less than 6% for both intra- and inter-assay in both studies and recoveries varied between 71 and 81%. The method was successfully applied to the determination of cimetidine in plasma for a pharmacokinetic study.

MeSH terms

  • Adolescent
  • Adult
  • Biological Availability
  • Chromatography, High Pressure Liquid / methods*
  • Cimetidine / blood*
  • Cimetidine / pharmacokinetics
  • Female
  • Humans
  • Male
  • Reproducibility of Results
  • Spectrophotometry, Ultraviolet


  • Cimetidine