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Controlled Drug Release from Monolithic Systems

  • J. Heller
Part of the FIDIA Research Series book series (FIDIA, volume 11)

Abstract

Controlled drug release from monolithic systems can be achieved by diffusion, swelling, or erosion. In diffusion-controlled systems the drug is dissolved or dispersed in a polymer matrix and allowed to diffuse from the monolith. In swelling-controlled systems the drug is immobilized in a glassy, hydrophilic polymer and is released as a swelling front moves into the matrix. In chemically controlled systems, rate of drug release is controlled by a combination of diffusion and erosion or in special cases, by erosion alone.

Keywords

Drug Release Maleic Anhydride Release Kinetic Control Drug Release Polymer Hydrolysis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Baker RW, Lonsdale HK (1974) Controlled release: mechanism and rates. In: Tanquary AC, Lacey RE, (eds): Controlled release of biologically active agents. Plenum Press, New York; pp 15–71CrossRefGoogle Scholar
  2. Beck LR, Ramos RA, Flowers CE Jr., Lopez GZ, Lewis DH, Cowsar DR (1981) Clinical evaluation of injectable biodegradable contraceptive systems. Am. J. Obstet. Gynecol. 140: 799–806Google Scholar
  3. Beck LR, Flowers CE Jr., Pope VZ, Wilborn WH, Tice TR (1983) Clinical evaluation of an improved injectable microcapsule contraceptive system. Am. J. Obstet. Gynecol. 147: 815–821Google Scholar
  4. Conix A (1958) Aromatic polyanhydrides, a new class of high melting fiber-forming polymers. J. Polymer Sci. 29: 343–353CrossRefGoogle Scholar
  5. Frazza EJ, Schmitt EE (1971) A new absorbable suture. J. Biomed. Mater. Res. Symp. 1: 43–58Google Scholar
  6. Heller J, Baker RW, Gale RM, Rodin JO (1978) Controlled drug release by polymer dissolution I. Partial esters of maleic anhydride copolymers. Properties and theory. J. Appl. Polymer Sci. 22: 1991–2009Google Scholar
  7. Heller J (1980) Controlled release of biologically active compounds from bioerodible polymers. Biomaterials 1: 51–57PubMedCrossRefGoogle Scholar
  8. Heller J, Penhale DWH, Helwing RF (1980) Preparation of poly(ortho esters) by the reaction of ketene acetals and polyols. J. Polymer Sci., Polymer Lett. Ed. 18: 619–624Google Scholar
  9. Heller J (1984) Biodegradable polymers in controlled drug delivery. CRC Critical Reviews in Therap. Drug Carrier Syst. 1: 39–90Google Scholar
  10. Heller J, Penhale DWH, Fritzinger BK, Ng SY (1984) Controlled release of contraceptive agents from poly(ortho esters). In: Zatuchni GK, Goldsmith A, Shelton JD, Sciarra J (eds): Long acting contraceptive delivery systems. Harper and Row, Philadelphia; pp 113–128Google Scholar
  11. Heller J (1985) Controlled drug release from poly(ortho esters)-a surface eroding polymer. J. Controlled Release 2: 167–177CrossRefGoogle Scholar
  12. Heller J, Fritzinger BK, Ng SY, and Penhale DWH (1985) In vitro and in vivo release of levonorgestrel from crosslinked poly(ortho esters) II crosslinked polymers. J. Controlled Release 1: 233–238CrossRefGoogle Scholar
  13. Heller J, Penhale DWH, Fritzinger BK, Ng SY (1987) The effect of copolymerized 9,10-dihydroxystearic acid on erosion rates of poly(ortho esters). J. Controlled Release, in pressGoogle Scholar
  14. Higuchi T (1961) Rates of release of medicaments from ointment bases containing drugs in suspension. J. Pharm. Sci. 50: 874–875PubMedCrossRefGoogle Scholar
  15. Hill JW, Carothers WC (1932) Studies of polymerization and ring formation XIV. A linear superpolyanhydride and a cyclic dimeric anhydride from sebacic acid. J. Am. Chem. Soc. 54: 1569–1579CrossRefGoogle Scholar
  16. Hsieh DST, Rhine WD, Langer R (1983) Zero-order controlled release polymer matrices for micro-and macromolecules. J. Pharm. Sol. 72: 17–22PubMedCrossRefGoogle Scholar
  17. Kulkarni RK, Pani KC, Neuman C, Leonard F (1966) Polylactic acid for surgical implants. Arch. Surg. 93: 839–843Google Scholar
  18. Langer R, Peppas N (1983) Chemical and physical structure of polymers as carriers for controlled release of bioactive agents: a review. Rev. Macromol. Chem. Phys. C23: 61–126Google Scholar
  19. Lee PI (1985) Kinetics of drug release from hydrogel matrices. J. Controlled Release 2: 277–288CrossRefGoogle Scholar
  20. Leong KW, Brott BC, Langer R (1985) Bioerodible polyanhydrides as drug-carrier matrices I: characterization, degradation, and release characteristics. J. Biomed. Mater. Res. 19: 941–955Google Scholar
  21. Sparer RV, Shih C, Ringeisen CD, Himmelstein KJ (1984) Controlled release from erodible poly(ortho ester) drug delivery systems. J. Controlled Release 1: 23–32CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1987

Authors and Affiliations

  • J. Heller
    • 1
  1. 1.Polymer Sciences DepartmentSRI InternationalMenlo ParkUSA

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