New Innovations in Testing Sustained-Release Tablets Using an Automated Dissolution System with Online Dilution

This paper describes the development and validation of an automated method for the dissolution testing of metformin hydrochloride for use in the quality assurance program. Automation could provide significant improvements in the consistency of results compared with existing manual methods. Care and consideration were given to the automation of preparation of samples and standards in line with current manual procedures. Reproducibility and sample preparation accuracy were quantified, and results obtained were compared against tests performed manually. The system was validated in accordance with the Chinese (1), European (2), and United States pharmacopeias (3) using salicylic acid. Salicylic acid testing for bath calibration also required dilution, which provided a direct comparison to the automated system used to test metformin hydrochloride tablets.