Objective: To establish the qualitative and quantitative methods of Caratostigma willmottianum.
Method: The roots of Radix Ceratostigmae were identified by TLC with the authentic medicinal material and plumbagin as the reference. The contents of plumbagin in Radix Ceratostigmae were determined by HPLC.
Result: The TLC method was simple and specific. A Diamonsil C18 column was used. The mobile phase was methanol-water (75:25). Plumbagin in the sawple extract was separated well. The linear range of plumbagin was 33.6-313.6 ng. The average recovery of plumbagin was 100.3% and RSD was 1.9%.
Conclusion: The methods can be used for identification and determination of plumbagin in C. willmottianum.