Polymers for Advanced Technologies Volume 6. p. 215

Polymeric Drug and Drug Administration, Raphael M. Ottenbrite, 'ed., ACS, Washington, DC (1994), ACS Symposium Series 545.

This is a symposium-based book developed from a symposium sponsored by the Division of Polymer Chemistry at the ACS meeting, Washington DC, August 1992. The book contains 19 chapters in the field of polymeric drugs and drug delivery systems. All the chapters describe original work, except for the first, written by the book editor, which is a brief overview of polymeric systems for biomedical appli- cations and serves as an introduction for the follow- ing chapters. The chapters are organized in a report format with introduction, experimental, and results and discussion sections. The book gives a broad view of the latest advances in medical applications of polymers which reflects the versatility of the chemistry and medical applications of biopolymers. The book focuses on two main topics, new delivery systems utilizing new or available polymers and polymeric biomaterials for use as polymeric drugs and prodrugs. Interesting chapters on delivery systems based on responsive polymers to external changes include: bioelastic polypeptides sensitive to changes in temperature and chemical potential, a protein device for glucose-sensitive release of insu- lin, and drug release from polymer films by electric stimulus. Acrylate hydrogels and polyethylene glycol-based delivery systems are used for oral de- livery of vaccines and drugs. New biodegradable compositions based on monomers such as lactide, trimethylene carbonate and hexamethylene diamine linked by ester and amide bonds are discussed. Discussions are provided on the synthesis and evalu- ation of biologically active polyanions and oligonucleotide-based polymers and anticancer polymer conjugates of 5-fluorouracil and adriamycin. The chapters touch upon the use of biopolymers in cancer treatment, diabetes, inflammatory processes, gastric ulcers, vaccine delivery, and for management of central nervous system conditions.

Although all chapters describe interesting work, a few chapters are of particular interest. Chapter 2

BOOK REVIEW

describes the synthesis and utilization of protein- based polymers capable of performing work as a result of changes in temperature, chemical potential, pressure or mechanical force. The concept is demon- strated by poly(G1y-Val-Gly-Val-Pro) crosslinked by y-irradiation which can increase some tenfold in volume on lowering the temperature from 37 to 0 "C. Interpolymer complexes of poly(ethyloxazo1ine) with poly(methacry1ic acid), and new composite polypyr- role films releasing drugs upon application of electro- chemical pulses are described in Chapters 7 and 8. Interesting results are presented in Chapter 13 de- scribing the effect of molecular weight of poly(viny1 alcohol) (PVA), on its accumulation in an-inflamma- tory site after intravenous administration in mice. This approach can be utilized for drug targeting to inflammatory sites using PVA drug conjugates. An example of the utilization of the polymeric prodrug approach to reduce side effects while maintaining therapeutic efficacy of the drug is demonstrated in Chapters 16 and 17. The anti-ulcer drug, misoprotol, bound to various polymers via a hydrolyzable sili- cone ether bond, was released in a controlled manner into the stomach (pH 1-2) and not in the intestine (pH >5), thus significantly reducing the drug side effects associated with systemic and intestinal expo- sure. 5-FU bound to 1,4-galactoseamine exhibited good efficacy with reduced side effects. The last chapter is somewhat unrelated and describes polymer-solvent inteactions studied with computa- tional chemistry using polyethylene glycol as model polymer.

This book emphasizes the versatility of biopoly- mers as active agents and as carriers for drug delivery systems. It should interest bioengineers, drug deli- very researchers and biopolymer chemists.

Abraham J. Domb The Hebrew University of Jerusalem

School of Pharmacy-Faculty of Medicine Jerusalem 91120

Israel