目的 建立RP-HPLC法测定穿心莲内酯中有关物质，并对穿心莲内酯原料进行不同影响因素的稳定性考察，了解影响其稳定性的具体因素。方法 采用反相高效液相色谱法，菲罗门Gemini C18色谱柱（250 mm×4.6 mm，5 μm），检测波长为224 nm，柱温为30 ℃，体积流量为1.0 mL/min，流动相为乙腈–甲醇–水梯度洗脱。考察穿心莲内酯原料药在不同pH值、氧化、高温、高湿、强光照条件下的稳定性。结果 穿心莲内酯及其3个有关物质得到了很好地分离，所建立的有关物质方法经验证，表明专属性、重复性及稳定性均良好。穿心莲内酯固体状态较为稳定；在溶液状态对氧化和pH 3～5条件较为稳定，在碱性介质、高温、光照条件下均不稳定。结论 该方法可以很好地用于穿心莲内酯的质量控制，穿心莲内酯在溶液状态下总体稳定性较差，该结果为穿心莲内酯及其相关制剂研究提供一定参考。

Objective To establish a selective RP-HPLC method for the determination of related substances in andrographolide, and to investigate the stability of them affected by different factors. Methods RP-HPLC method was used on Phenomenex Gemini C18 column (250 mm × 4.6 mm, 5 μm) at the temperature of 30 ℃. The mobile phases consisted of acetonitrile, methanol, and water. The flow rate was set at 1.0 mL/min and the UV detection was performed at 224 nm. This method was applied to evaluate the stability of andrographolide in solid and liquid forms by the following conditions: different pH values, oxidation, high temperature, high humidity, and strong light. Results The andrographolide and three related substances were separated. The developed method was further validated and proved to be sensitive, precise, and stable. The andrographolide in solid state was stable relatively, and its liquid state was also stable relatively in oxidation and pH 3－5 conditions; however in the conditions of alkaline, high temperature and light, andrographolide was proved not to be stable. Conclusion The method is successfully applied to the quality control of andrographolide. The andrographolide in liquid state has poor stability, and the results could give some references for the preparation study.