WHITEHALL LABS' LYCD NEEDS A CHEMICAL REFERENCE STANDARD

WHITEHALL LABS' LYCD NEEDS A CHEMICAL REFERENCE STANDARD on which to base assay procedures, FDA told the firm in a June 15 letter. "Minimal requirements of specifications [of LYCD] should include characteristics comparable in approach to the USP requirements for extracts of cascara sagrada and belladonna. . . These extracts have assay procedures which are based on the chemical materials responsible for the activity of the extracts," FDA stated. The agency's letter, which responded to a February 6 comment by Whitehall, said that the information, in the comment and in previous submissions, is not sufficient to allow for final classification of the ingredient LYCD (live yeast cell derivative). Whitehall has requested that LYCD be placed in Category I as a wound healing aid. LYCD is now in Category III. In describing the reference standard for belladonna extract, FDA said that "no similar standard appears to be identified for LYCD." The agency added that "other attributes would have to be based on the class of compounds ultimately identified as the active principle of the LYCD." FDA also said that the filtering process used to make LYCD and the fermentation of the yeast cells need to be described. "The equipment used for fermentation and extraction should be described as well as the specifications for the raw material used for fermentation and the extraction." The agency provided additional reasons why Whitehall's comment lacked adequate data to characterize LYCD: "a definitive assay for the active moiety(ies) is missing; the material should be sterile, rather than carry a requirement for meeting a microbial content test for a USP reagent; all quality control tests should have detailed descriptions of their test procedures." FDA noted that no stability data was included. "Yeast extract is generally recognized as an unstable material for some uses [and] biological activity after storage should be demonstrated for a proposed period of expiry," FDA stated.