Photosensitizing compositions for medical applications, namely, pharmaceuticals for the treatment of infectious diseases caused by bacteria, fungi, viruses, and any other disease-causing micro-organisms; light-activated disinfectant compositions for killing disease-causing micro-organisms; light-activated therapeutic preparations for photodisinfection; photosensitizers for use in photodynamic therapy and/or photodisinfection, namely, pharmaceuticals for the treatment of infectious diseases ca...