184 JOURNAL OF COSMETIC SCIENCE cussed. Certain types of diseased skin are more permeable than normal, intact skin. Other variables include hydration, tem- perature, contact time, and anatomic site. The final chapter teaches when and how to apply percutaneous absorption measurements to meet four major objec- tives: transdermal development, formula- tion of dermatologicals, safety assessment of cosmetics, and risk assessment following dermal exposure to hazardous environ- mental or occupational chemicals. Trans- dermal products target the circulation, and so standard techniques for monitoring bioavailability, i.e., blood level profiles, are utilized. In the case of dermatologic preparations, blood concentrations are usually below detection limits. In vitro comparisons utilizing excised human skin or a relevant animal substitute are useful in formulation but are not yet accepted as a bioavailability standard by regulatory agencies. Systemic toxicity following skin exposure is a function of the inherent tox- icity of the compound in question and its absorption efficiency. For recognized tox- ins, the biological implications are known the percutaneous absorption must be esti- mated or measured. This book is highly recommended for scientists working in the areas of develop- ment of topical products and toxicology following topical exposure. Those involved in regulatory affairs related to dermato- logicals and cosmetics may also benefit.- Joel L. Zatz--Rutgers University

j. Cosmet. Sci., 49, 185-212 (May/June 1998) Preprints of the 1998 Annual Scientific Seminar May 7-8, 1998 Westin Hotel Seattle, WA 185