Determination of Critical Influencing Factor on pH Stability of Yuxingcao Injection

The change of drug quality of Yuxingcao injection after formulation is considered as one of the causes for adverse reactions. In this study, orthogonal experimental design was used to investigate the influencing factors on the pH stability of Yuxingcao injection. Two methods of accelerated tests were carried out in the experiments. The results showed that using Tween 80 as the solubilizer could significantly decrease the pH value of Yuxingcao injection after accelerated tests. There was no significant difference in the pH value after the accelerated tests when the other 6 factors varied, including the type of liquid processed, the dosage of activated carbon, heating temperature, reagents for pH adjustment, pH value range after adjustment, and sterilization conditions. In order to improve the quality stability of Yuxingcao injection, the quality of Tween 80 should be strictly controlled to minimize the change of pH value of Yuxingcao injection.