Regulation of allergen extracts in the United States *

Allergen extracts are the most widely used allergy diagnostic and immunotherapeutic reagents worldwide. In this chapter, the authors discuss the regulation of these important products in the United States, the differences in regulation of standardized and nonstandardized products, and the additional potency determinations used for the labeling of standardized allergen extracts. In addition, the authors discuss the statistical basis on which bioequivalence may be established between allergen extracts and a reference standard, or a new product to an existing extract. The underlying considerations of allergen potency are specific to the allergen extracts themselves, and these differences are discussed in detail.