290 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS NOTICE 'Members of the Society may borrow books from the library at The Chemists' Club, 52 East Forty-first Street, New York. The library is located on the mezzanine and open Monday through Friday, 9:00 a.m. to 5:00 p.m.

ION EXCHANGE RESINS AND THEIR APPLICATIONS TO DRUG AND COSMETIC PRODUCTS By ROBERT W. P•v,c•v^•* Presented •anuary 9, 1962, Chicago SINCE THEIR INTRODUCTION in 1948, synthetic ion exchange resins have played an important role in the field of biochemistry. The unique properties of ion exchange resins received early attention in the phar- maceutical industry where they were used as active ingredients in antacid formulations (1), sodium reduction therapy products (2), gastro and acidity indicators (3), as well as intestinal absorbants (4). Their wide range of uses in analytical procedures and processing applications for the recovery and purification of antibiotics, vitamins, alkaloids, amino acids, etc., has il- lustrated that ion exchange resins are perhaps one of the most versatile chemicals available to the modern day chemist. As understanding of the equilibria and kinetics of ion exchange resins developed, especially of their inter-reaction with the electrolyte environment of the gastro intestinal tract, the principles of ion exchange were soon applied by the pharmaceutical chemist to the development of a unique basic approach to the modification of oral drug compounds. Today, a host of drug preparations, utilizing an ion exchange resin mechanism of drug release, are receiving considerable attention by the medical pro- fession because of their unique properties. They achieve sustained re- lease and prolonged drug action (5) and, as a result, provide a reduction of drug toxicity and side effects (6). They stabilize drugs (7) as well as provide a reliable approach to tablet disintegration (8) and taste masking. In recent years, the work of Thurmon (9), Thorns (10, 11) and Richardson (12) has illustrated the broad utility of ion exchange resins as a new funda- mental approach to the development of highly effective therapeutic and cosmetic topical products. The concept of ion exchange has been applied to the chemistry of the skin, where the standard reactions of ion exchange polymers--neutralization, ion interchange and deionization--have been utilized to achieve such desirable effects on the skin as: * Rohm & Haas Company, Resinous Products Div., Philadelphia 5, Pa. 291