Liquid chromatographic determination of allopurinol in tablets: collaborative study.

A liquid chromatographic method for the determination of allopurinol in tablets was collaboratively studied by 7 laboratories. The method uses a C18 reverse phase column, a 0.05M ammonium phosphate mobile phase, hypoxanthine as the internal standard, and photometric detection at 254 nm. Collaborators were supplied with samples of 2 commercial tablets and 1 synthetic tablet powder. The mean recovery value of allopurinol from the synthetic tablet powder was 100.0%. The combined mean coefficient of variation for all 3 types of sample analyzed was less than 2%. The method has been adopted official first action.