Objective: To investigate the stability of oridonin (ORI) solution for research and development of novel ORI prepartions.
Method: The effect of pH on the degradation rate of ORI was evaluated, the pH values of the oridonin solutions were adjusted to the setting pH, with 1 mol x L(-1) HCl or NaOH, respectively, and stored at room temperature for 60 h. The constant temperature method was applied to evaluate the stability of ORI solution at room temperature and at 4 degrees C.
Result: The pH-rate profile of ORI was V-shaped, and the pHm was 5. The t90 of ORI solution at room temperature was 53.2 h and 91.5 h at 4 degrees C CONCLUSION: The ORI solution is not stable. The pH-dependent degradation of ORI solution confirms to specific acid-base catalysis reaction.