Improved chromatographic assessment of Chinese medicinal products by multi-chemical classes analysis

An improved strategy for the quality evaluation of proprietary Chinese medicines (PCM) in complex matrices is presented. It involves the simultaneous separating and displaying of multi-chemical classes and analytes within a single chromatographic elution. The developed fingerprints have the properties of better coverage of multi-chemical classes among the composing herbs. This comprehensive and more facile approach was illustrated for Lemai Keli, a commonly used PCM listed in the Chinese Pharmacopoeia with highly complex analytical matrices. Ten marker compounds belonging to monoterpene glycosides, chalcone glycosides, phenolic acids and phenolic carboxylic aldehyde groups of the analytes together with three common chromatographic peaks were successively separated and displayed within the chromatographic window as a unique HPLC-PAD fingerprint. Rigorous method validation data demonstrated the suitability of the current method for quality assessment purposes in a highly complex PCM matrix. Additional chemometric treatment further demonstrated the uniqueness of the developed fingerprint, with a distinctive chemical profile compared to a highly similar PCM formulation (Kangen Karyu) from which it was considered to be impossible to differentiate when using the conventional single marker approach.