Studies On Stability Of A New Drug Combination With Sesquiterpene Lactones

There were a great deal of reports on the pharmacological action of bilobalide and ginkgolide C at home and abroad, but few involved their stability. This increased the hidden danger behind the production and transport of raw material and preparation. This paper systematically studied the influencing factor, accelerated stability and long-term stability of raw material and freeze-dried powder preparation. Besides, we also investigated the influence of sterilization and pH.The results of influencing factor test, accelerated test, long-term stability test showed good stability of bilobalide and ginkgolide C, but significant content degradation was observed under the condition of autoclaving in a time-dependent manner. This phenomenon illustrated that bilobalide and ginkgolide C were not suitable for being prepared as fluid acupuncture, so we choose the dosage of freeze-dried powder, which can avoid the content decrease caused by sterilization.Finally, we investigated the impact of alkali on the stability of bilobalide and ginkgolide C. We found that bilobalide and ginkgolide C were stable under acidic condition. Under alkaline condition the lactone ring of ginkgolide C opened. When the pH decreased to acid the ring reclosed. However, bilobalide was not stable under alkaline condition, and decomposed into many catabolite. We studied the impact of different amount of alkali and different reaction temperature on the stability of the ring-opening product of bilobalide. Moreover we separated one decomposition product by silica gel column chromatography and detected with HPLC.