Pharmaceutical Research

, Volume 9, Issue 10, pp 1279–1283 | Cite as

Molecular Weight Changes in Polymer Erosion

  • Antony D’Emanuele
  • Jennifer Hill
  • Janet A. Tamada
  • Abraham J. Domb
  • Robert Langer

Abstract

We report a study of the effects of polymer molecular weight on the erosion of polyanhydride copolymer matrices composed of 1,3-bis (p-carboxyphenoxy)-propane (CPP) and sebacic acid (SA) in aqueous solution. The erosion profile characteristically displays an induction period during which the erosion rate is relatively slow. The length of this period depends on the initial molecular weight of the polymer. The induction period may be characterized as a time during which a rapid decrease in polymer molecular weight occurs, the end of this period correlating with the time required for the polymer molecular weight to decrease to below a value of approximately 5000 (MW).

drug delivery system erodible polymers polyanhydrides induction period molecular weight 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

REFERENCES

  1. 1.
    K. W. Leong, B. C. Brott, and R. Langer. Bioerodible polyanhydrides as drug-carrier matrices. I. Characterization, degradation and release characteristics. J. Biomed. Mat. Res. 19:941–955 (1985).Google Scholar
  2. 2.
    S. J. Holland, B. J. Tighe, and P. L. Gould. Polymers for biodegradable medical devices, part I. J. Control. Release 4:155–180 (1986).Google Scholar
  3. 3.
    F. G. Hutchinson and B. J. A. Furr. Drug carrier systems. In F. H. D. Roerdink and A. M. Kroon (eds.), Biodegradable Polymers for Controlled Release of Peptides and Proteins, John Wiley and Sons, Chichester, 1989, pp. 111–127.Google Scholar
  4. 4.
    R. Langer and M. Chasin. In R. Langer and M. Chasin (eds.), Biodegradable Polymers as Drug Delivery Systems, Marcel Dekker, New York, 1990, pp. 43–70.Google Scholar
  5. 5.
    J. P. Kitchell and D. L. Wise. Poly(lactic/glycolic acid) biodegradable drugpolymer matrix systems. Meth. Enzymol. 112 (Drug Enzyme Targeting, Pt. A):436–448 (1985).Google Scholar
  6. 6.
    M. Chasin, D. Lewis, and R. Langer. Polyanhydrides for controlled drug delivery. Biopharm. Manuf. 1:33–39 (1988).Google Scholar
  7. 7.
    K. W. Leong, P. D'Amore, M. Marletta, and R. Langer. Bioerodible polyanhydrides as drug-carrier matrices: II: Biocompatibility and chemical reactivity. J. Biomed. Mater. Res. 20:51–64 (1986).Google Scholar
  8. 8.
    M. Chasin, A. Domb, E. Ron, E. Mathiowitz, R. Langer, K. Leong, C. Laurencin, H. Brem, and S. Grossman. Polyanhydrides as drug delivery systems. In M. Chasin and R. Langer (eds.), Biodegradable Polymers as Drug Delivery Systems, Marcel Dekker, New York, 1990, pp. 43–69.Google Scholar
  9. 9.
    A. Domb and R. Langer. Solid-state and solution stability of polyesters and polyanhydrides. Macromolecules 22:2117 (1989).Google Scholar
  10. 10.
    H. G. Rosen, J. Chang, G. Wnek, R. Linhardt, and R. Langer. Bioerodible polyanhydrides for controlled drug delivery. Biomaterials 4:131–133 (1983).Google Scholar
  11. 11.
    K. Leong, J. Kost, E. Mathiowitz, and R. Langer. Polyanhydrides for the controlled release of bioactive agents. Biomaterials 7: 364–371 (1986).Google Scholar
  12. 12.
    A. D'Emanuele, J. Kost, J. Hill, and R. Langer. The investigation of the effects of ultrasound on degradable polyanhydride matrices. Macromolecules 25:511–515 (1992).Google Scholar
  13. 13.
    J. Tamada and R. S. Langer. Mechanism of the erosion of polyanhydride drug delivery systems. Proc. Int. Symp. Control. Rel. Bioact. Mater. 17, Controlled Release Society, Lincolnshire, IL, 1990, paper D305.Google Scholar
  14. 14.
    H. Fukuzaki, H. Yoshida, M. Asano, M. Kumakura, T. Mashimo, H. Yuasa, K. Imai, and H. Yamanaka. In vivo characteristics of low-molecular-weight copoly(L-lactic acid/DL-hydroxyisocaproic acid) with parabolic-type and s-type degradation patterns. Makromol. Chem. 191:731–736 (1990).Google Scholar
  15. 15.
    Y. Doi, Y. Kanesawa, M. Kunioka, and T. Saito. Biodegradation of microbial copolyesters: Poly(3-hydroxybutyrate-CO-3-hydroxyvalerate) and poly(3-hydroxybutyrate-CO-4-hydroxybutyrate). Macromolecules 23:26–31 (1990).Google Scholar
  16. 16.
    S. J. Holland, A. M. Jolly, M. Yasin, and B. J. Tighe. Polymers for biodegradable medical devices, Part II. Biomaterials 8:289–295 (1987).Google Scholar
  17. 17.
    S. J. Holland, M. Yasin, and B. J. Tighe. Polymers for biodegradable medical devices, Part VII. Biomaterials 11:206–215 (1990).Google Scholar
  18. 18.
    H. T. Wang, H. Palmer, R. J. Linhardt, D. R. Flanagan, and E. Schmitt. Degradation of poly(ester) microspheres. Biomaterials 11:679–685 (1990).Google Scholar
  19. 19.
    C. G. Pitt. Poly-ε-caprolactone and its copolymers. In M. Chasin and R. Langer (eds.), Biodegradable Polymers as Drug Delivery Systems, Marcel Dekker, New York, 1990, pp. 71–120.Google Scholar

Copyright information

© Plenum Publishing Corporation 1992

Authors and Affiliations

  • Antony D’Emanuele
    • 1
  • Jennifer Hill
    • 1
  • Janet A. Tamada
    • 1
  • Abraham J. Domb
    • 3
  • Robert Langer
    • 1
  1. 1.Department of Chemical EngineeringMassachusetts Institute of TechnologyCambridge
  2. 2.Department of PharmacyUniversity of ManchesterManchesterU.K.
  3. 3.School of Pharmacy, Faculty of Medicine, Department of Pharmaceutical ChemistryThe Hebrew University of JerusalemJerusalemIsrael
  4. 4.Massachusetts Institute of TechnologyCambridge

Personalised recommendations