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BioMed Research International
Volume 2013 (2013), Article ID 607351, 11 pages
Research Article

Novel Poly(L-lactide-co-ε-caprolactone) Matrices Obtained with the Use of Zr[Acac]4 as Nontoxic Initiator for Long-Term Release of Immunosuppressive Drugs

1Centre of Polymer and Carbon Materials, Polish Academy of Sciences, M. Curie Sklodowskiej 34, 41-819 Zabrze, Poland
2Department of Biopharmacy, School of Pharmacy, Medical University of Silesia, Narcyzow 1, 41-200 Sosnowiec, Poland
3Institut Europeen des Membranes, UMR CNRS 5635, Universite Montpellier 2, Place Eugene Bataillon, 34095 Montpellier, France
4Jan Dlugosz University in Czestochowa, Institute of Chemistry, Environmental Protection and Biotechnology, Armii Krajowej 13, 42-100 Czestochowa, Poland

Received 26 April 2013; Accepted 16 August 2013

Academic Editor: Eder Lilia Romero

Copyright © 2013 Katarzyna Jelonek et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Slowly degradable copolymers of L-lactide and ε-caprolactone can provide long-term delivery and may be interesting as alternative release systems of cyclosporine A (CyA) and rapamycin (sirolimus), in which available dosage forms cause a lot of side effects. The aim of this study was to obtain slowly degradable matrices containing immunosuppressive drug from PLACL initiated by nontoxic Zr[Acac]4. Three kinds of poly(L-lactide-co-ε-caprolactone) (PLACL) matrices with different copolymer chain microstructure were used to compare the release process of cyclosporine A and rapamycine. The influence of copolymer chain microstructure on drug release rate and profile was also analyzed. The determined parameters could be used to tailor drug release by synthesis of demanded polymeric drug carrier. The studied copolymers were characterized at the beginning and during the degradation process of the polymeric matrices by NMR spectroscopy, GPC (gel permeation chromatography), and DSC (differential scanning calorimetry). Different drug release profiles have been observed from each kind of copolymer. The correlation between drug release process and changes of copolymer microstructure during degradation process was noticed. It was determined that different copolymer composition (e.g., lower amount of caprolactone units) does not have to influence the drug release, but even small changes in copolymer randomness affect this process.