Selection, Evaluation, and Control of the Assay of the Pharmaceutical Product III: Statistical and Economic Evaluation of the Three-Component Infrared Spectrophotometric Assay of Aspirin Anhydride

An experimental design of a series of three-component infrared spectrophotometric assays of various preparations of aspirin anhydride is statistically analyzed. Methods are shown for the proper choice of standards and the economical design of assays for a desired statistical confidence. Information as to stability and significance of physicochemical properties, such as melting point, is also obtained.