High performance liquid chromatog.-mass spectrometry was selected as the detection method, and oxidants with degradation effects were used for intervention.At the same time, adjustments and controls were made to the amount of solvents and oxidants added.Through experiments, understand the changes in factors such as the amount of excipients added to sustained-release formulations, heating time, and temperature, and evaluate the amount of NDMA generated.Potassium sulfate and sodium hypochlorite in sustained-release formulations have a synergistic oxidation effect, and the synergistic reaction between the two can promote the degradation of metformin hydrochloride into NDMA.By selecting low temperature oxidant excipients and controlling temperature and time indicators, the generation of NDMA can be reduced.When using residual oxidants as excipients, it is required to consider safety indicators, carry out quality control work during this period, improve the quality monitoring level of excipients, and pay attention to the compatibility between excipients.