Our product, HOWELT® Famotidine, Calcium Carbonate and Magnesium Hydroxide Chewable Tablets, originally adhered to a quality standard drafted and established by the Guangdong Institute for Drug Control. This standard adopted the manual titration method for calcium and magnesium ions, with the endpoint determined by observing color changes with the naked eye — a method significantly influenced by human subjective factors. Differences in observations among different operators easily lead to deviations in test results, making it difficult to ensure the accuracy and consistency of product quality determination.

To address this technical challenge, we conducted specialized technical research and innovatively established a “fully automated potentiometric titration method”. We systematically prepared method validation instructions, a comparative analysis of the old and new methods, and recommendations for standard revisions, then submitted an application for quality standard modification to the National Medical Products Administration (NMPA). After rigorous experimental verification and technical review by the Institute for Drug Control, it was confirmed that this fully automated potentiometric titration method was significantly superior to the original manual method in terms of feasibility, result accuracy, and repeatability. Subsequently, the new version of the quality standard was drafted with this method as the core.

Finally, the NMPA reviewed and approved the standard. The revised national quality standard for Famotidine, Calcium Carbonate and Magnesium Hydroxide Chewable Tablets was officially released (Standard No.: WS1-XG-016-2016). It was promulgated on June 15, 2016, and fully implemented starting from December 15, 2016.