Novel Approaches and Applications of Steroid Hormone Delivery Via Poly(Dimethylsiloxane)
Poly(dimethylsiloxane) has been used to deliver steroid hormones to animals since the 1960’s and commercial poly-(dimethylsiloxane) based delivery systems for estradiol and progestins are currently available. Studies were conducted with androgens to develop poly(dimethylsiloxane) delivery systems that would maintain relatively constant blood testosterone concentrations in ruminant females for six months. All androgens tested passed through the poly(dimethylsiloxane) in vivo at rates proportional to surface area and increased blood testosterone concentrations relatively proportionally to the secretion rate. Implants with testosterone propionate incorporated in poly(dimethylsiloxane): (1) maintained relatively constant blood testosterone concentrations in vivo for six months and maintained more constant blood testosterone concentrations than commercially available implants (nonpoly (dimethylsiloxane) containing testosterone propionate, (2) evoked an anabolic effect in heifers, (3) maintained male sexual behavior in female ruminants and (4) prenatally androgenized female ruminants. The poly(dimethylsiloxane) implants not only facilitated therapy but also enhanced efficacy and in some cases eliminated side effects.
KeywordsTestosterone Concentration Silicone Elastomer Silicone Implant Propionate Testosterone Testosterone Propionate
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- 3.D. M. Long, Jr. & J. Folkman, U.S. Patent 3,279,996 (1966).Google Scholar
- 5.V. Lee & J. R. Robinson, In: “Sustained and Controlled Release Drug Delivery Systems”, J. R. Robinson, Ed., Marcel Dekker, Inc., New York, 1985.Google Scholar
- 6.Y. W. Chien, In: “Sustained and Controlled Release Drug Delivery Systems”, J. R. Robinson, Ed., Marcel Dekker, Inc., New York, 1978.Google Scholar
- 7.Y. W. Chien & H. J. Lambert, U.S. Patent 3,946,106 (1976).Google Scholar
- 8.J. M. Anderson, Proc. Internat. Symp. Controlled Release of Bioactive Materials, Controlled Release Society, Toronto, Canada, 1987, p. 1.Google Scholar
- 10.A. A. Sinkula, In: “Sustained and Controlled Release Drug Delivery Systems”, J. R. Robinson, Ed., Marcel Dekker, Inc., New York, 1978.Google Scholar
- 11.K. Heide & H. G. Schwick, In: “Handbook of Experimental Immunology”, D. M. Weir, Ed., Blackwell, Oxford, England, 1978.Google Scholar
- 17.K. Tojo, Y. Sun & Y. W. Chien in: “Proc, Internat. Controlled Release of Bioactive Materials”, Controlled Release Society, Geneva, Switzerland, 1985, p.153.Google Scholar
- 19.L. L. Berger & D. J. Kesler, U.S. Patent (Filed 7/28/1986; U.S. Serial Number 891,151).Google Scholar
- 20.K. C. DeHaan, L. L. Berger, D. J. Kesler, F. K. McKeith, D. L. Thomas & T. G. Nash, J. Anim. Sci., 65, 1465 (1987).Google Scholar
- 21.K. C. DeHaan, L. L. Berger, D. J. Kesler, F. K. McKeith, D. B. Faulkner & G. F. Cmarik, J. Anim. Sci., in press.Google Scholar
- 22.I. J. Clarke, R. J. Scarmuzzi & R. V. Short, J. Embryol. Exp. Morph., 6, 87 (1976).Google Scholar