[Study on stability of oridonin solution].

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.