Evaluation of new benzoporphyrin derivatives with enhanced PDT efficacy

A first report on the biological evaluation of a series of isomerically pure benzoporphyrin derivatives (cis- and trans-isomers) as methyl esters is described. In preliminary in vivo studies, the n-hexyl ether analogues of both cis- and trans-isomers of benzoporphyrin derivatives were found to be more active than the industrially prepared benzoporphyrin derivative, a mixture of monocarboxylic acids (BPDMA, Quadralogic Technologies, Vancouver). Further studies with 4-de-vinyl-4- (1-hexyloxyethyl) benzoporphyrin derivative showed that, like BPDMA, it had reduced residual skin phototoxicity compared in mice with Photofrin. The uptake and clearance characteristics of BPDMA were also compared with the 4-(1-hexyloxyethyl)-derivative by in vivo reflection spectroscopy.