Standardization, Quality Assurance and Regulations

The variation in phytochemical levels between Echinacea preparations is apparent. Many researchers have suggested that standardization of phytochemicals in Echinacea products is needed. However, standardization of the products is difficult due to the complexity of the phytochemicals, the lack of understanding regarding interaction between individual phytochemicals 

The CAP are commonly used as marker compounds and labeled as phenolics on many dietary supplements. However, general spectroscopic methods used for determining total phenols can sometimes give erroneous readings. Targeting specific compounds would be more advantageous and provide additional information such as plant species/variety and parts of the plants used in the preparation. 

A reversed-phase (LiChroCART 125-4 column) system with gradient elution is an effective method for separating the CAP within 12 min (Bauer, 1999b). The gradient system included water plus 0.1% orthophosphoric acid (85%) as eluent A and acetonitrile plus 0.1% orthophosphoric acid (85%) as eluent B. A linear gradient from 10 to 30% eluent B was completed within 20 min at 1 ml/min and detection at 330 nm. Bergeron et al. (2000) modified the method to include a pH adjustment to 2.80 for a solvent system containing phosphoric acid (solvent A) and 1% phosphoric acid (1 M) in acetonitrile (solvent B). 

Gas chromatography (GC)-MS coupled with multivariate statistical analysis proved valuable in verifying the authenticity of Echinacea species (Lienert et al, 1998). Similar root extracts could be grouped, based on the identified compounds from the GC-run, by principal component and cluster analysis. The correct grouping of the Echinacea species (i.e., purpurea, angustifolia, and pallida) was not influenced by the extraction method or by the aging process of the roots. 

Echinacea is sold as a dietary supplement in the United States and as a natural health product in Canada. However, Health Canada does support the use of Echinacea in food products thus functional foods could be developed for the Canadian market. In the United States and Canada, there are no restrictions on the species/varieties used in products. In Germany and many European countries, Echinacea products are sold as drugs in pharmacies (Bauer, 2000). In addition, not all products are approved for use in all countries. For example, E. purpurea aerial parts and E. pallida roots are approved in Germany whereas E. angustifolia and E. purpurea roots are not (Blumenthal, 1998). 

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