利福昔明的杂质A和杂质B的稳定性研究

Stability Research on the Impurity A and Impurity B of Rifaximin

[目的]研究自制的利福昔明杂质A和杂质B与利福昔明在不同条件下的变化规律。[方法]在酸、碱、氧化、高温的条件下,采用高效液相色谱法测定利福昔明及其有关物质含量。[结果]在1 mol/L HCl和1 mol/L NaOH溶液条件下,杂质A和杂质B均不稳定,在1 ml双氧水的条件下,杂质A非常稳定,而杂质B不稳定。杂质B在100℃下可部分转化为杂质A。[结论]在较高温度下,杂质B可部分转化为杂质A,在酸、碱条件下杂质A和杂质B均不稳定。

[Objective] To study the variation of the rifaximin and the two prepared impurities in different conditions.[Method] The contents and related substances of the two unknown impurities were determined by RP-HPLC method in the condition of acid,alkali,oxidation and high temperature.[Result] The two impurities were found very unstable in acid and alkali as 1M hydrochloric acid and 1M sodium hydroxide solution.But the impurity A was found very stable in the 1M hydrogen peroxide solution,nor the impurity B.And the impurity B was found converted to the impurity A in the 100 centigrade partial.[Conclusion] The two unknown impurities were found very unstable in the acid and alkali condition.But the impurity B can be converted into the impurity A partial in the high temperature condition.