Development and validation of a quantification method for α-humulene and trans-caryophyllene in Cordia verbenacea by high performance liquid chromatography

Abstract

Acheflan® herbal medicine is the first medicine developed and produced in Brazil using Cordia verbenacea DC., Boraginaceae, essential oil as a constituent. C. verbenacea has anti-inflammatory properties, which have been directly related to α-humulene and trans-caryophyllene. Currently, the quantification of α-humulene and trans-caryophyllene in C. verbenacea has only been described by GC-MS. Although this technique is widely used it cannot be directly applied to finished medicinal products since they contain aqueous constituents. In this context, the objective of this work was to develop a methodology for quantifying C. verbenacea in raw materials and in pharmaceutical formulations using liquid chromatography. The Box–Behnken experimental design was used successfully to optimize the analytical method. The method developed in this study was validated and proven to be effective in the proper separation of α-humulene and trans-caryophyllene. In addition, the developed method was applied to commercial formulations (cream and aerosol) containing C. verbenacea essential oil, which resulted in very satisfactory separation without interference from excipients. C. verbenacea oil contains four times higher concentrations of trans-caryophyllene than α-humulene. Therefore, we propose that trans-caryophyllene can be used as a marker of C. verbenacea essential oil. Evaluation of trans-caryophyllene content would be especially valuable for applications where the concentrations are very low such as in permeation and release studies of dermatological formulations.