Objective To investigate influence of pH value on the stability of hyoscine btylbromide in solutions.Methods An HPLC method was employed to determine the concentration of tropic acid, a hydrolysis degradation product of Hyoscine Btylbromide. The degradation curves of hyoscine btylbromide under different pH conditions were obtained by regulation analysis between proportion of the concentration of tropic acid and time. Results Hyoscine btylbromide was stable in solutions with pH value between 5. 6 and 2. 0, while degradation increased with the decreasing of pH value from 2. 0 to 1. 0. Conclusion Hyoscine btylbromide is unstable under low acid condition.
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