Document b5wbmx04w0Nv8nYYL97Nae0e1

Joseph Campau at the &Detroit, M ichigan 48232 Telephone (313) 567-5300 Quality Comrol and ^ Governmen' Regulations Division PARKE-DAVIS December 19, 1973 Hearing Clerk Food and Drug Administration Room 6-86 5600 Fishers LanRockville, Maryland Gentlemen: As a manufacturer of biological and pharmaceutical (both oral and parenteral) products, Parke, Davis & Company is an interested person concerning. the Commissioner's proposals and related petition on asbestos in fQfpd and drugs as published in the Federal Register of September 28, 3.973, page 27076. We are, of bourse, aware of the occupational risks in asbestos mines causing astiestosis. The risks of inhalation of dusts seem well established. The evidence of risk of malignancy following injection of asbestos particles in liquid suspension or the ingestion of asbes tos particles, as in talc, however, is as stated, contradictory and inconclusive. Asbestos-containing filters have long been used in the manufac ture of biological products. Their advantages include their basic effectiveness as.; filters as well as reported depyogenizing effects and the adsorption of undesirable components including active viral particles in the.manufacture of tissue culture vaccines. The proposals contained in the notice have been carefully con sidered by our people responsible for development and production of filtered products. In general, we believe the proposal to replace asbestos-contaiiSing filters with membrane filtration systems (includ ing a follow-up .filter to pick up asbestos particles) may be possible except for application to certain high concentration blood-protein products. These include such important products as Immune Serum Globulin (Human)., Tetanus Immune Globulin (Human) and 25% Normal Serum Albumin (Human). ..continued.. 'OcZQ?l Heading Clerk 4 2- - December 19, 1973 .., ,,While efforts are being made to develop filtration processes to meet the proposed requirements of 133.8, p. 27080, current evidence is that these products prepared from the source materials we, die cannot be membrane filtered at temperatures required to pre vent the possible development of pyrogens. Required proof that the uge ,of non-asbestos-containing membrane filters will compromise the safety or potency of these products is not available and would require considerable time to develop, assuming it is possible to do so at all. .. For this reason, we conclude that we cannot fully meet the pro posed stipulations of 133.8 currently and in the foreseeable future. Certainly before any such requirement were to be made effective we must request time to permit the development of suitable filters and techniques to assure continuation of the manufacture of these biolo gical so vital to the public health. With respect to the proposal in 133.6 to require talc to pass the.test specified in 121.2006, talc meeting this specification is available from certain vendor sources and, as far as is known, should continue to be supplied. Our technical people have expressed the opinion that the proposed analytical procedures and maximum allowable limits based on such pro posed analytical methods in 121.2006 are satisfactory for the two general categories of asbestos, i.e. chrysotile and amphibole asbestos (amosite; crocidolite; and fibrous anthophyllite, tremolite, and actindlite). However, we request that equal acceptance and recognition be. given to microscopical dispersion staining techniques, especially those dispersion staining procedures applicable to the detection and identification of chrysotile asbestos. It is recommended that the use of the dispersion staining approach be accepted to simplify and improve microscopic evaluation of talc for chrysotile and, where applicable, fo t,,femolite and other amphibole asbestos. We appreciate the opportunity to comment on this proposal. As requested, five copies of this letter are enclosed. Very truly yours, PARKE, DAVIS & COMPANY LML'/DEM: ldw ace President, Quality Control and Government Regulations