A final rule amending 21 CFR 680.4 was published on October 8, 1987; the publication of this regulation removed the specific methodology of the Antigen E potency test from the CFR, permitting CBER to introduce test methods for determining relative potency of Allergenic Extracts by way of an alternate mechanism. In the January 1986 workshop, the first four extracts targeted for standardization, (Extracts of Cat, Timothy pollen, June pollen and Perennial Rye grass pollen) and the tests to be performed on these products were discussed with manufacturers. Standardization efforts have focused on Timothy, June, Perennial Rye, Bermuda and Orchard grass extracts with a total of 19 applications now under review. Each extract submitted by a company is analyzed for its isoelectric focusing pattern, IgE binding activity by Blotted RadioImmuno ElectroFocusing (BRIEF), total protein content, and RAST relative potency compared to CBER reference extracts. In order to facilitate the standardization of pollen extracts, LAP currently supplies all testing reagents and references to the companies. Ongoing testing is needed to replenish laboratory supplies of these items. Selected candidate references are constantly being evaluated in the laboratory for concurrent clinical testing. Preliminary investigations into the standardization of other pollen extracts (i.e. Redtop grass) are in progress.
