chapter one Site-specific drug delivery using liposomes as carriers* Contents Introduction. 3 II.Liposomes in drug delivery. 4 Phospholipids. III.The liposome-drug concept. A. Liposome size. B. Targeting ligands. 7 IV. Liposomes as carriers of therapeutic agents. .12 A. Application. .12 B. Manufacturers. .14 V.Recent advances. .16 Highlights of current research .17 VI Concluding remarks References. 26 I. Introduction Over the past three decades,significant advances have been made in drug delivery technology.This effort,pioneered by Alza Laboratories of Palo Alto Califo n:12 Drug delivery has now become a multidisciplinary science consisting of biopharmaceutics and pharmacokinetics.Great strides have also been made p池m and J.B.Lippincott Publishing Company,Philadelphia,PA. 33 chapter one Site-specific drug delivery using liposomes as carriers* Contents I. Introduction .3 II. Liposomes in drug delivery.4 A. Regional drug delivery .4 B. Chemical characteristics of liposomes.5 C. Phospholipids .6 III. The liposome-drug concept.7 A. Liposome size .7 B. Targeting ligands.7 C. Problems .8 D. Manufacturing issues .8 IV. Liposomes as carriers of therapeutic agents .12 A. Application.12 B. Manufacturers.14 V. Recent advances .16 A. Highlights of current research .17 VI. Concluding remarks .25 References.26 I. Introduction Over the past three decades, significant advances have been made in drug delivery technology. This effort, pioneered by Alza Laboratories of Palo Alto, California,1,2 among others, has been accelerated in recent years due to the substantial decline in the development of new drug entities. Drug delivery has now become a multidisciplinary science consisting of biopharmaceutics and pharmacokinetics. Great strides have also been made * Adapted from Ranade, V.V., Drug delivery systems. 1. Site specific drug delivery using liposomes as carriers, J. Clin. Pharmacol., 29, 685, 1989. With permission of the J. Clin. Pharmacol., and J.B. Lippincott Publishing Company, Philadelphia, PA