Volume 42 of "Progress in Drug Research" contains seven reviews and the various indexes which facilitate its use and establish the con nection with the previous volumes. The articles in this volume deal with organization and management of drug research; luteinizing hor mone regulators; natural products as anticancer agents; flavonoids and their pharmacological activity; serenics in the control of mental disturbances; Transfer Factor and its application and with Transfer Factor in malignancy. In the 34 years that "Progress in Drug Research" has existed, the Edi tor has enjoyed the valuable help and advice of many colleagues. Readers, the authors of the reviews, and last but not least, the review ers have all contributed greatly to the success of this series. Although the comments received so far have generally been favorable, it is nevertheless necessary to analyze and to reassess the current position and the future direction of such a review series. So far, it has been the Editors intention to help disseminate informa tion on the vast domain of drug research, and to provide the reader with a tool with which to keep abreast of the latest developments and trends. The reviews in PDR are useful to the non-specialists, who can obtain an overview of a particular field of drug research in a rela tively short time."

Volume 43 of "Progress in Drug Research" contains five reviews and the various indexes which facilitate its use and establish the connection with the previous volumes. The articles in this volume deal with high cholesterol blood levels and other dyslipidemias; search of ideal antihypertensive drugs; the natural PQlyamines and the immune system; biologically active quinazolones and with production and action of interferons. In the 35 years the PDR has existed, the Editor has enjoyed the valuable help and advice of many colleagues. Readers, the authors of the reviews, and last but not least, the reviewers have all contributed greatly to the success of this series. Although the comments received so far have generally been favorable, it is nevertheless necessary to analyze and to reassess the current position and the future direction of such a review series. So far, it has been the Editors intention to help disseminate information on the vast domain of drug research, and to provide the reader with a tool with which to keep abreast of the latest developments and trends. The reviews in PDR are useful to the non-specialist, who can obtain an overview of a particular field of drug research in a relatively short time. The specialist readers of PDR will appreciate the reviews' comprehensive bibliographies, and, in addition, they may even get fresh impulses for their own research. Finally, the readers can use the 43 volumes of PDR as an encyclopedic source of information.

Multi-component crystalline systems or co-crystals have received tremendous attention from academia and industry alike in the past decade. Applications of co-crystals are varied and are likely to positively impact a wide range of industries dealing with molecular solids. Co-crystallization has been used to improve the properties and performance of materials from pharmaceuticals to energetic materials, as well as for separation of compounds. This book combines co-crystal applications of commercial and practical interest from diverse fields in to a single volume. It also examines effective structural design of co-crystals, and provides insights into practical synthesis and characterization techniques. Providing a useful resource for postgraduate students new to applied co-crystal research and crystal engineering, it will also be of interest to established researchers in academia or industry.