Liquid chromatographic determination of cephalexin preparations interlaboratory validation

A previously published column liquid chromatographic method proposed for the analysis of cephalexin preparations was subjected to an interlaboratory validation. The method was rigorously defined in terms of performance requirements, yet allowed a degree of flexibility to the individual analyst. Nine participating laboratories submitted results for the analysis of bulk drug substance, capsules and powder for oral suspension. Estimates of the within-laboratory standard deviation, the between-laboratories standard deviation, repeatability relative standard deviation and reproducibility relative standard deviation of the results of the analysis of cephalexin preparations were found to be 0.34, 2.01, 0.32 and 1.94%, respectively.