Chinese Medicine Regulatory Office

Analysis of Chemical Markers of Chinese Materia Medica (CMM) in Medicinal Oil for External Use

Analysis of Chemical Markers of Chinese Materia Medica (CMM) in Medicinal Oil for External Use

This research project aims at developing and validating testing methods for the determination of chemical markers of Chinese materia medica (CMM) commonly found in Chinese medicinal oil for external use. This project is divided into two phases. In the first phase, a test method for the determination of 5 chemical markers (α-pinene, eucalyptol, camphor, menthol and methyl salicylate) was developed and validated. In the second phase, test methods for the analysis of other 7 chemical markers (borneol, cinnamaldehyde, citronellal, eugenol, linalool, linalyl acetate and thymol) were developed and validated. All the methods were validated according to the requirements stipulated by HOKLAS and Technical Guidelines for proprietary Chinese medicines (pCm) registration.


  • Validated multi-analytes testing methods;
  • Convenient, simple, easy and common testing methods;
  • Provide dual chromatographic columns approach for choice and in case negative control sample is not available, can demonstrate specificity of the method when analyzing the chemical markers in external medicinal oil*;
  • Use of advanced instrumentation for the analysis of chemical markers present at sub-percentage level.


The aim of this project is to provide analytical method(s) for Chinese Medicines traders and testing sectors as reference. They can adopt the multi-analytes testing methods as the quality control method for pCm registration. This would help to reduce the investment on method development and validation. In addition, the manufacturer of pCm could adopt the testing method as their internal quality control protocol to strengthen quality control ability of their products and establish the brand image of Hong Kong in Chinese medicines.

Testing Methods

*The method is intended to provide a reliable analytical method that can be used as quality control method for Chinese medicinal oil with active ingredients containing one or more of the 12 chemical markers, such as turpentine oil, eucalyptus oil, camphor, menthol, methyl salicylate, borneol, cinnamon oil, citronellal oil, clove oil, lavender oil and thyme oil. It is the user’s responsibility to assess the suitability of the Chinese medicinal oil products when adopting this method, especially whether other ingredient(s) or excipient(s) contain any of the 12 chemical markers of choice as well as the existence of other herbal material(s)/herbal material extract(s).