Liposomal formulations of hydrophobic photosensitizer for photodynamic therapy

Abstract

Pharmaceutical liposomal formulations are described for photodynamic therapy comprising a, hydrophobic porphyrin photosensitizer, a monosaccharide and one or more synthetic phospholipids, which are stable in storage especially through freeze-drying process. The liposomal formulations provide therapeutically effective amounts of the photosensitizer for intravenous administration. In particular derivatives of chlorins and bacteriochlorins, such as temoporfin, are, hydrophobic photosensitizers whose efficacy and safety are enhanced by such liposomal formulations. The formulation can be efficiently freeze-dried preserving the size of the liposomal vehicles, and the content of a therapeutically effective amount of the photosensitizer, due to the selection of phospholipids and monosaccharides. The invention also relates to liposome compositions formed upon reconstitution with an aqueous vehicle. The freeze-dried formulation upon reconstitution with a suitable aqueous vehicle forms liposomes that are useful for intravenous administration.