Controlled Release of Pesticides and Pharmaceuticals

337 Pages·1981·24.096 MB·English

by  Donald R. Cowsar (auth.), Danny H. Lewis (eds.)

Danny H. Lewis Editor
Controlled Release
of Pesticides and
Pharmaceuticals
Controlled Release of
Pesticides and
Pharmaceuticals
Controlled Release of
Pesticides and
Pharmaceuticals
Edited by
Danny 11. Lewis
Southern Research Institute
Birmingham, Alabama
SPRINGER SCIENCE+BUSINESS MEDIA, LLC
Library of Congress Cataloging in pubLication Data
International Symposium on Controlled Release of Bioactive Materials (7th:
1980: Ft. Lauderdale, Fla.)
Controlled release of pesticides and pharmaceuticals.
"Proceedings of the Seventh International Symposium on Controlled
Release of Bioactive Materials, held July 27-30, 1980, in Ft. Lauderdale,
Florida" -T.p. verso.
Includes bibliographies and index.
1. Delayed-action preparations-Congresses. 2. Pesticides, Controlled
release-Congresses. 1. Lewis, Danny H. II. Title.
RS201.D4157 1980 615' .191 81-7336
ISBN 978-1-4757-0739-7 ISBN 978-1-4757-0737-3 (eBook) AACR2
DOI 10.1007/978-1-4757-0737-3
Proceedings of the Seventh International 5ymposium on
Controlled Release of Bioactive Materials, held July 27 -30,
1980, in Ft. Lauderdale, Florida
© 1981 Springer Science+Business Media New York
Originally published by Plenum Press, New York in 1981
AII rights reserved
No part of this book may be reproduced, stored in a retrieval system, or transmitted,
in any form or by any means, electronic, mechanical. photocopying, microfilming,
record ing, or otherwise, without written permission from the Publisher
PREFACE
This volume is a result of the 7th International Symposium
on Controlled Release of Bioactive Materials held in Ft. Lauderdale,
Florida, on July 27-30, 1980. Controlled-release technology has
rapidly emerged over the past decade as a new science offering novel
approaches to a variety of practical problems in health care, food
production, and ecology. These symposia, organized and held annually
by the Controlled Release Society, Inc., provide an opportunity
for exchange of information among research scientists, regulatory
agencies, and consumers. The symposia are unique in the diverse
disciplines represented among the participants. Included among
the 186 attendees representing more than a dozen countries at the
1980 meeting were chemists, engineers, biologists, entomologists,
botanists, pharmacologists, physicians, and many others representing
the pharmaceutical, veterinary, and agrochemical areas.
Each paper contained in this volume was reviewed and refereed
by experts in the field of controlled-release technology. The
assistance of the approximately 30 referees involved in that task
is greatly appreciated.
The efforts of the many people involved in organ1z1ng the
meeting and preparing the manuscripts are appreciated. Particularly
helpful were Mr. Don Davis and his staff at Southern Research
Iustitute who did the graphic arts and layout. Special thanks are
due to Dr. Howard Creed for his editorial assistance and to Mrs.
Doris Thrower,' who typed the complete volume in final form.
The administrative and technical assistance provided by Southern
Research Institute in the preparation of this volume is appreciated.
D.H. Lewis
March, 1981
CONTENTS
Controlled Release: Benefits vs. Risks • • • • • • • • • • • 1
Donald R. Cowsar
Experimental Approaches for Achieving Both Zero-Order and
Modulated Controlled Release from Polymer Matrix
Systems • • • • • • • . • • • . 5
Dean S.T. Hsieh and Robert Langer
Pharamacokinetic Modeling of Gentamicin Release from a
Prosthetic Heart Valve. • • • • • • • • • 17
L.S. Olanoff, J.M. Anderson, and R.D. Jones
Controlled Drug Release from Polymeric Matrices Involving
Moving Boundaries • . . • • . • • • . . . • • • • • 39
P. I. Lee
Anthracycline-DNA Complexes as Slow-Release Preparations
in the Treatment of Acute Leukemia. • . • • • 49
Curt Peterson, Christer Paul, and Gosta Gahrton
Biological Activities and Targeting of Soluble
Macromolecules. • • . • • • • ••.•• 67
Josef Pitha and John W. Kusiak
Hydrophilic/Hydrophobic Control of Steroid Release from a
Cortisol - Polyglutamic Acid Sustained Release
System. • • . . • . • • . • • • • • . • • • • 79
N. Tani, M. Van Dress, and J.M. Anderson
Potential Delivery of Contraceptive Agents to the
Female Reproductive Tract • . • • • • 99
David L. Gardner, David J. Fink, and Craig R. Hassler
Release of Drugs from IUDs Using an Ethylene Vinyl
Acetate Matrix. • . • • • • •...••• 111
R.G. Wheeler and P.G. Friel
vii
viii CONTENTS
Fibrous Polymers for the Delivery of Contraceptive
Steroids to the Female Reproductive Tract • . 125
Richard L. Dunn, Danny H. Lewis, and Lee R. Beck
Controlled Release of Metribuzin, 2,4,-D, and Model
Aromatic Amines from Polysaccharides and
Poly(Vinyl Alcohol) •••..••.•...• 147
C.L. McCormick, K.W. Anderson, J.A. Pelezo, and
D.K. Lichatowich
Synthesis and Properties of Urea Formaldehyde Resins
Generating 2,6-Dichlorobenzonitrile ... 159
Etienne H. Schacht, Guido E. Desmarets, and
Eric J. Goethals
Polymers Containing Pendent Insecticides. . . . . • • • . • • 171
William E. Meyers, Danny H. Lewis, Robert K. VanderMeer,
and Clifford S. Lofgren
Antifouling Polymers: Room-Temperature-Curing
Organotin Polymers •........ 191
R.V. Subramanian and K.N. Somasekharan
Synthesis and Properties of New Copolymers and
Terpolymers with Pendent Organotin Moieties 203
N.A. Ghanem, N.N. Messiha, N.E. Ikladious, and
A.F. Shaaban
Characterization of Bioactive Organotin Polymers:
Fractionation and Determination of MW by SEC-GFAA 219
E.J. Parks and F.E. Brinckman
Controlled-Release Organotin Pesticides Biochemistry:
Toxicology : Environmental Factors .•. 239
Nate Cardarelli, William Evans, and Daniel Smith
Optimal Formulations with Phantolid for Extending the
Duration of Effectiveness of Trimedlure and Methyl
(~)-6-Nonenoate as Attractants to Male Mediterranean
Fruit Flies . . . • • . . • . . . . • . • 245
Irving Keiser, Martin Jacobson, and James A. Silva
Controlled-Release Formulations and their use in
Insect Crop Protection. 259
Norman L. Gauthier
Controlled Release Temephos: Laboratory and Field
Evaluations . . • . • • 275
Thomas J. Quick, Nathan F. Cardarelli, Ruben J. Ellin,
and Larry R. Sherman
CONTENTS ix
Tri-n-Butyltin Fluoride as a Controlled-Release
Mosquito Larvicide •...•••...•. 287
L.R. Sherman and J.C. Jackson
Fermentation Per Se as a Biological Slow Delivery
Mechanism for Releasing Cofactors of Fruit
Fly Attractants . . . . . . . . . . . . . . 295
Irving Keiser and Nobel Wakabayashi
Implantable Systems for Delivery of Insect Growth
Regulators to Livestock.!! ....... . 303
H. Jaffe, P.A. Giang, O.K. Hayes, J.A. Miller, and
B.H. Stroud
Sustained-Release Systems for Livestock Pest Control. . . • . 311
J.A. Miller, S.E. Kunz, and D.O. Oehler
Controlled-Release Feed Additives for Ruminants: I.
Cellulose-Based Coating Compositions for
Rumen-Stable Nutrients ..... . 319
Stephen H. wu, Clarence C. Dannelly, and
Ronald J. Komarek
List of Contributors. 333
Index . 337
CONTROLLED RELEASE: BENEFITS VS. RISKS
Donald R. Cowsar
Southern Research Institute
2000 Ninth Avenue South
Birmingham, Alabama 35255
During the decade of the 1970s, new controlled-release tech
nology continued to emerge from research laboratories around the
world. A few controlled-release formulations and devices have
already reached the market place, and many others are currently
undergoing premarketing trials. One might say that controlled
release has transgressed from its infancy through its childhood,
and it is rapidly maturing to occupy a vital position in many im
portant industries. The future of controlled release appears bright
indeed.
The science and technology of controlled release is clearly
multidiciplinary. The non-routine interactions among polymer
chemists, biologists, biochemists, agrochemists, etomologists,
physical pharmacists, physicians, dentists, veterinarians, engineers,
and others have provided the synergism required for major technical
innovations. In 1855, when E. Fick stated in his emprical First
Law of Diffusion that "the flow is proportional to the gradient
in concentration", I am certain he never dreamed that Folkman and
Long1 would apply the law to formulate a zero-order delivery system
for cardiac drugs or that Baker and Lonsdale2 would derive fifty
two ancillary equations quantifying controlled release by diffusion
from devices of many different geometries. Today, at least 1000
controlled-release scientists throughout the world publish their
work each year in journals ranging from Mosquito News to the Pro
ceedings of the National Academy of Sciences.
When contrasted to conventional drug and pesticide formulary,
controlled release offers many benefits, some small and some very
large. To obtain benefits of large magnitude, one sometimes has
to take substantial risk. Fortunately, with nearly all of the
2 D. R. COWSAR
controlled-release formulations developed so far, the risk to indivi
duals and the environment appears minimized while the benefits appear
maximized. Indeed, a significant benefit of many agrochemical con
trolled-release formulations is that they minimize environmental
risks. Some of the major benefits of controlled release are sum
marized below.
A fundamental limitation of conventional formulations is that
they give up their agent to the surrounding medium at time-varying
rates that are highest initially and decline continually thereafter.
The rate of decline (duration of action) usually depends not upon
the dose but upon the host, and much more of the agent is required
to prolong the action than one might anticipate. Controlled-release
technologists, on the other hand, have developed a new arsenal of
"smart" systems which deliver agents with precision at predeter
mined, low rates. In many instances the agents are delivered
directly to the target organ or organism with only minimal inter
vention, and hence, only minimal therapeutic or environmental risk.
At least one order of magnitude less agent is usually required when
the delivery system provides a constant (zero-order) release rate.
Given that agents are efficacious, i.e., that they are effective
for the purpose intended, conventional formulations have failed
because of faulty compliance by the user with the prescribed regimen.
Since most controlled-release formulations are designed to function
for prolonged periods after a single administration, user compliance
rarely compromises their efficacy. In fact, some agents which were
only marginally efficacious when formulated conventionally, have
become highly effective in controlled-release formulations. If,
however, unexpected side effects occur with agents administered
via controlled release, many controlled-release formulations are
not reversible, and the side effects persist until the dose regimen
is complete. The more severe are the side effects, the greater
the risk.
As mentioned earlier, Fickian diffusion is often the mechanism
by which agents are released from controlled-release formulations.
Similarly, diffusion through cell walls is usually the mechanism
by which agents are taken up by the target organisms. For poorly
diffusing agents, uptake can only be increased by increasing the
extracellular concentration, i.e., the amount of agent administered
in each dose. Thus, agent uptake rather than agent release becomes
the controlling factor. By entrapping poorly diffusing agents in
tiny lipid spherules (i.e., liposomes), controlled-release tech
nologists have produced formulations of conventional agents with
greatly enhanced potency. The liposomes are transported intact
through cell walls, and the entrapped agents are released slowly
within the cells as lipase enzymes attack the lipid materials.
The potential benefits of liposomes appear large indeed, while the