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Formulation of Benzoporphyrin Derivatives in Pluronics ¶
Author(s) -
Chowdhary Rubinah K.,
Chansarkar Namrata,
Sharif Isha,
Hioka Noboru,
Dolphin David
Publication year - 2003
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/0031-8655(2003)0770299fobdip2.0.co2
Subject(s) - poloxamer , copolymer , micelle , aqueous solution , emulsion , particle size , materials science , chemistry , dynamic light scattering , chemical engineering , polymer chemistry , organic chemistry , nanotechnology , polymer , nanoparticle , engineering
This study investigates the potential of Pluronics for the formulation of tetrapyrrole‐based photosensitizers, with a particular focus on B‐ring benzoporphyrin derivatives. TheB‐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. Out of a range of different commercially available block copolymers studied, it was found that the longer the hydrophobic block, the better the stabilization of tetrapyrrolic drugs in monomeric form in aqueous suspensions. Of these the best performance was observed in the micelle‐forming Pluronic P123. Micelle size determination by laser light scattering confirmed that particle size in stable Pluronic formulations was around 20 nm. Pluronics such as L122 formed emulsions spontaneously without the need for emulsion stabilizers; emulsions were highly stable at ambient temperatures over several days and also highly effective as potential drug delivery agents.