Ephedra adulteration

FDA proposes new rules regarding ephedra, which would have considered some products containing ephedra as adulterated supplements, making them subject to FDA regulation. The FDA based its adul-... 

Phinney et al. developed three CE-UV methods that allowed the enantiose-paration of ephedrine and pseudoephedrine using neutral HP-pCD, DM-pCD, and charged sulfated pCD as chiral selectors. The combination of negatively charged sulfated pCD (2.8 %) and DM-pCD (1.2 %) under acidic conditions (pH 2.5) provided the best separation of the two couples of enantiomers. Standard reference materials (SRMs) containing ephedra in development at NIST were analyzed by each of three CE methods. In the SRM samples, only the naturally occurring enantiomers ( )-ephedrine and (-l-)-pseudoephedrine were found however, the method proved to be suitable in detecting product adulteration by its potential in identification of specific stereoisomers [56]. The neutral HP-pCD was also found to be a useful chiral selector in the presence of tetrabutylammonium chloride as additive, for the simultaneous enantioseparation of ephedrine, pseudoephedrine, iV-methylephedrine, and norephedrine enantiomers in Ephedra sinica extracts [57]. 

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