Liquid chromatographic determination of acetaminophen in tablets: collaborative study

A reverse phase liquid chromatographic method previously reported for the determination of acetaminophen in tablets was collaboratively studied by 5 laboratories. Each collaborator received duplicate samples of a synthetic tablet formulation and 3 powdered commercial tablet composites. The composites represented single-component and multi-component proprietary products and a single-component generic product. The pooled repeatability (CVDo) and reproducibility (CVDx) values for the proprietary tablets were 0.89 and 1.34%, respectively. For the generic tablets, these values were 0.66 and 0.74%, respectively. The pooled recovery value for acetaminophen added to the synthetic formulation was 98.9 +/- 0.7% (n = 10) with a CV of 0.75%, CVDo of 0.37%, and CVDx of 0.78%. The overall repeatability of the method was 0.64%, and the overall reproducibility was 0.95%. The method has been adopted official first action.