A biodegradable injectable thermoplastic for localized camptothecin delivery

Authors

  • A. Hatefi,

    1. Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada K7L 3N6
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  • D. Knight,

    1. Department of Chemical Engineering, Queen's University, Kingston, Ontario, Canada K7L 3N6
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  • B. Amsden

    Corresponding author
    1. Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada K7L 3N6
    2. Department of Chemical Engineering, Queen's University, Kingston, Ontario, Canada K7L 3N6
    • Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada K7L 3N6. Telephone: 613-533-3093; Fax: 613-533-6637
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Abstract

Camptothecin is an example of a potent drug with a short half-life that would benefit from a localized drug depot system that maintains its stability prior to being released. For this reason, a thermoplastic, biodegradable polymer drug depot was prepared and characterized, and the in vitro release of camptothecin examined. ε-Caprolactone oligomers were prepared by ring-opening polymerization initiated by various alcohols. The polymers were characterized via differential scanning calorimeter (DSC) for thermal transitions, and via a parallel plate rheometer for melt viscosity. Camptothecin was loaded into the oligomers and released into PBS buffer. The viscosity of the oligomers was alterable by the initiator used. The oligomers were semi-crystalline with melting points between 37 and 45°C. Camptothecin was released from the oligomers in a diffusion-controlled manner, with the release rate increasing as the melt viscosity of the oligomer decreased. The unreleased camptothecin remained in its active lactone form for a period of up to 16 weeks. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:1195–1204, 2004

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