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The Scientific World Journal
Volume 2012, Article ID 126723, 8 pages
http://dx.doi.org/10.1100/2012/126723
Research Article

Temperature-Sensitive Gels for Intratumoral Delivery of β-Lapachone: Effect of Cyclodextrins and Ethanol

1Faculdade de Ciências da Saúde, Universidade de Brasília (UnB), Campus Universitário Darcy Ribeiro, 70910-900 Brasília-DF, Brazil
2Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Campus Vida, Universidad de Santiago, 15782 Santiago de Compostela, Spain

Received 20 October 2011; Accepted 15 January 2012

Academic Editors: D. Quintanar-Guerrero and A. Savaser

Copyright © 2012 Marcilio S. S. Cunha-Filho 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.

Abstract

This work evaluated the potential of Pluronics (varieties F127 and P123) in combination with solubilizing agents to be used as syringeable in situ gelling depots of intratumoral β-lapachone (βLAP). Pluronic dispersions prepared at various concentrations in the absence and the presence of ethanol and randomly methylated β-cyclodextrin (RMβCD) were characterized regarding their rheological properties, drug solubilization capacity, and in vitro release. Pluronic F127 (18–23%) formulations combined high ability to solubilize βLAP (enhancement solubility factor up to 50), adequate gel temperature range (over 25°C), and gel strength at 37°C enough to guarantee the permanence of the formulation in the administration site for a period of time. βLAP release rate was finely tuned by the concentration of the polymer and the addition of RMβCD (diffusion coefficient ranging between 9 and 69 μg·cm−2). The ethanol increases βLAP release rate but simultaneously led to weak gels. This paper shows that βLAP formulations involving temperature-reversible Pluronic gels may be suitable for intratumoral drug delivery purposes.