This book contains the proceedings of the International Symposium on Ophthalmie Drug Delivery, which was held in Pisa in October 1986. Topical ophthalmic therapy is a matter of interest to specialists from different fields (medical, pharmaceutical, chemical, technological, etc.), who, unfortunately, have a tendency to meet separately, thus limiting a diffusion of knowledge, ideas and experience that would greatly favour the overall pro- gress in this area of research. The Symposium, for the first time in Europe, provided the opportunity for specialists from different disciplines and from different countfies to meet, to discuss and to share their experience. This multidisciplinary approach is reflected in the wide variety of topics that appear in the book. The papers are aimed at reviewing many of the complex, interrelated, medical pharmaceutical and technological facets of topical ophthalmic therapy. lt is our hope that they may stimulate further thought in this fascinating field, and may provide possible guidelines for future research. The editors wish to express their appreciation to the sponsors of the Symposium: Fidia Research Laboratories, whose generosity permitted the meeting tobe held, and the ltalian National Research Council (CNR, Progetto Finalizzato Chimica Fine e Secondaria) who gave its scientific tutorship. Thanks are also due to the other Symposium contributors, ACRAF SpA, Rome, and Allergan Italia SpA, Rome. The assistance, support and coopera- tion given before, during and after the Symposium by Dr. Patrizia Chetoni, Dr. Maria Tilde Torracca and Dr. Elena Parolini arealso gratefully acknowledged.