Determination of cimetidine and metabolites in plasma by reversed-phase high-performance liquid chromatographic...

A high-performance liquid chromatographic method for the detection of cimetidine and its metabolites in plasma was developed which has a short analysis time and good resolution. The total analysis time was approximately 11 min. The standard curves were linear over the concentrations used for all compounds and the sensitivity limits were good. The coefficient of variation for within-day and between-day analysis was less than 4.2% for all compounds with the exception of guanyl urea cimetidine, which was approximately 10%. Currently, this assay is being used in a pharmacokinetic study of plasma and gastric aspirate samples obtained from a critically ill pediatric population.