Stability and scanning electron microscopy of Photofrin-II and Photosan-3

In this article we report studies on the stability of Photofrin-II and Photosan-3 by inducing porphyrin disaggregation and monitoring changes in the UV/Vis absorption and fluorescence spectra. It was observed that the aggregates in Photosan-3 are more stable than those in Photofrin-II, which may be due to a higher protoporphyrin content in Photosan-3. We also present scanning electron microscopy pictures of lyophilized Photofrin-II and Photosan-3, that both show porphyrin micelles in various shapes, including large lamellar layers, with small rods and cones attached to them.