Capillary electrophoresis to analyze water-soluble oligo(hydroxyacids) issued from degraded or biodegraded aliphatic polyesters

  • C. Braud
  • R. Devarieux
  • H. Garreau
  • M. Vert


In an attempt to increase the range of analytical techniques able to monitor ultimate degradation stages of degradable, biodegradable, and bioresorbable polymers, capillary zone electrophoresis (CZE) was used to analyze tentatively oligomers formed during thermal condensation of lactic, glycolic, anddl-3-hydroxybutyric acids. The influence of the buffer and of capillary coating are discussed in terms of electroosmotic flow. Typical analyses were first performed using a 0.1M borate buffer (pH 8.9) with anodic injection. In the case of lactic acid, seven peaks were well separated, while only three peaks were observed for glycolic acid. A more complex situation was found fordl-3-hydroxybutyric acid oligomers. The first five peaks were split. The major component of each doublet was attributed to hydroxy-terminated oligomers, whereas the satellite peaks were assigned to oligomers bearing a C=C double bond at the noncarboxylic terminus. CZE of pH-sensitive lactic acid oligomers was also performed in 0.05M phosphate buffer (pH 6.8) with cathodic injection after physical coating of the fused-silica capillary with DEAE-Dextran. The buffer-soluble fraction present in lactic acid oligomers was extracted from a dichloromethane solution. Extracts issued from different batches of lactic acid condensates gave a constant water-solubility pattern whose cutoff was at the level of the decamer. CZE was also used to monitor thein vitro aging of aqueous solutions of these water-soluble oligomers. The lactyllactic acid dimer appeared more stable than higher oligomers, thus showing that ultimate stages of the degradation did not proceed at random. These physicochemical characteristics were used to complement the degradation pathway based on diffusion of oligomers duringin vitro aging of large size lactic acid plates made by compression molding. CZE data showed that lactic acid was the only component which was released in the aqueous medium during degradation.

Key words

Capillary zone electrophoresis oligomers lactic acid glycolic acid 3-hydroxybutyric acid water solubility stability degradation 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    M. Vert, J. Feijen, A. Albertsson, G. Scott, and E. Chiellini (1992)Biodegradable Polymers and Plastics, Royal Society of Chemistry, Cambridge.Google Scholar
  2. 2.
    Y. Doi and K. Fukuda (1994)Biodegradable Plastics and Polymers, Elsevier, Amsterdam.Google Scholar
  3. 3.
    B. L. Karger, A. S. Cohen, and A. Guttman (1989)J. Chromatogr. 492, 585–614.PubMedGoogle Scholar
  4. 4.
    W. Nashabeth and Z. El Rassi (1990)J. Chromatogr. 514, 57–64.Google Scholar
  5. 5.
    J. Liu, O. Shirota, and M. Novotny (1991)J. Chromatogr. 559, 223–235.PubMedGoogle Scholar
  6. 6.
    J. B. L. Damm, G. T. Overklift, B. W. M. Vermeulen, C. F. Fluitsma, and G. K. van Dedem (1992)J. Chromatogr. 608, 297–309.PubMedGoogle Scholar
  7. 7.
    J. T. Smith and Z. El Rassi (1992)J. High Res. Chromatogr. 15, 573–578.Google Scholar
  8. 8.
    P. J. Oefner and C. Chiesa (1994)Glycobiology 4, 397–412.PubMedGoogle Scholar
  9. 9.
    C. Braud and M. Vert (1992)Polym. Bull. 29, 177–183.Google Scholar
  10. 10.
    J. Bullock (1993)J. Chromatogr. 645, 169–177.Google Scholar
  11. 11.
    R. Kuhn and S. Hoffsteter-Kuhn (1993)Capillary Electrophoresis: Principles and Practice, Springer-Verlag, Berlin.Google Scholar
  12. 12.
    F. Foret, L. Krivankova, and P. Boceck (1993)Capillary Zone Electrophoresis, VCH, Weinheim.Google Scholar
  13. 13.
    C. Vidil, C. Braud, H. Garreau, and M. Vert (1995)J. Chromatogr. 711, 323–329.Google Scholar
  14. 14.
    S. M. Li, H. Garreau, and M. Vert (1990)J. Mater. Sci. Mater. Med. 1, 123–130.Google Scholar
  15. 15.
    I. Grizzi, H. Garreau, S. Li, and M. Vert (1995)Biomaterials 16, 305–311.PubMedGoogle Scholar
  16. 16.
    S. Li and M. Vert (1995) in G. Scott and D. Gilead (Eds.),Degradable Polymers—Principles and Applications, Chapman and Hall, London, pp. 43–87.Google Scholar
  17. 17.
    M. Vert, F. Chabot, J. Leray, and P. Christel (1978) French Patent application No. 78-29978.Google Scholar
  18. 18.
    M. P. Richards and P. J. Aagaard (1994)J. Cap. Elec. 1, 90–95.Google Scholar
  19. 19.
    N. Cohen and E. Grushka (1994)J. Cap. Elec. 1, 112–115.Google Scholar
  20. 20.
    G. Schomburg, D. Belder, M. Gilges, and S. Motsch (1994)J. Cap. Elec. 1, 219–230.Google Scholar
  21. 21.
    C. H. Holten (1971)Lactic Acid—Properties and Chemistry of Lactic Acid and Derivatives, Verlag Chemie, Weinheim.Google Scholar
  22. 22.
    J. Mauduit (1991) Ph.D. thesis, Rouen, France.Google Scholar
  23. 23.
    D. W. McLellan and P. J. Halling (1988)J. Chromatogr. 445, 251–257.Google Scholar
  24. 24.
    S. Karlsson, C. Sares, R. Renstad, and A.-C. Albertsson (1994)J. Chromatogr. 669, 97–102.Google Scholar
  25. 25.
    S. Terabe and T. Isemura (1990)J. Chromatogr. 515, 667–676.Google Scholar
  26. 26.
    M. Vert, A. Torres, S. M. Li, S. Roussos, and H. Garreau (1994) in Y. Doy and K. Fukuda (Eds.),Biodegradable Plastics and Polymers, Elsevier, Amsterdam, pp. 11–23.Google Scholar

Copyright information

© Plenum Publishing Corporation 1996

Authors and Affiliations

  • C. Braud
    • 1
  • R. Devarieux
    • 1
  • H. Garreau
    • 1
  • M. Vert
    • 1
  1. 1.CRBA-URA CNRS 1465, Faculté de PharmacieUniversité de Montpellier 1MontpellierFrance

Personalised recommendations