Correlation of photosensitizer delivery to lipoproteins and efficacy in tumor and arthritis mouse models; comparison of lipid-based and Pluronic P123 formulations.

Purpose: The purpose of this study was the use of animal models to demonstrate the importance of drug delivery (verteporfin) to plasma lipoproteins in order to attain efficacy of photodynamic therapy (PDT) in vivo.

Methods: Photosensitizers appropriately formulated in various vehicles such as pluronics and lipid-based systems were compared to delivery of the drug in DMSO in two in vivo systems. The first was a tumor model using male DBA/2 mice inoculated intradermally with M1 rhabdomyosarcoma cells and in the second, arthritis in the MRL -lpr mouse strain was enhanced by two intradermal injections of complete Freunds adjunct.

Formulation of benzoporphyrin derivatives in Pluronics.

This study investigates the potential of Pluronics for the formulation of tetrapyrrole-based photosensitizers, with a particular focus on B-ring benzoporphyrin derivatives. The B-ring derivatives have a high tendency to aggregate in aqueous solutions, and this poses a significant formulation problem. Pluronics are ABA-type triblock copolymers composed of a central hydrophobic polypropylene oxide section with two hydrophilic polyethylene oxide sections of equal length at either end.