[Study on extraction process of the volatile oil for biyuan dropping pills].

OBJECTIVE: To determine the optimal extracting process of the volatile oil for Biyuan Dropping Pills. METHODS: Conditions for the extraction were studied by orthogonal design guided by the increasement of the volatile oil. RESULTS: The distilling time is the main factor,and the fineness of the herbal material is the second. The optimal process is as follows: crush the herbal material into coarse powder, macerate 1 hour with 9 times water and distill 4 hours. CONCLUSION: The optimized process is feasible and stable.