mmmCompositions which are stable in storage and a method of production of pharmaceutical based nanoparticutate formulations for clinical use in photodynamic therapy comprising a hydrophobic photosensitizer poly(lactic co glycolic) acid and stabilizing agents are provided. These nanoparticulate pharmaceutical formulations provide therapeutically effective amounts of photosensitizer for parenteral administration. In particular tetrapyrrole derivatives can be used as photosensitizers whose efficacy and safety are enhanced by such nanoparticulate formulations. It also leaches the method of preparing PLGA based nanoparticles under sterile conditions. In one of the preferred embodiments of the present invention PLGA based nanoparticles have a mean particle size less than 500nm and the photosensitizer is temoporf?n 5 10 15 20 tetrakis(3 hydroxyphenyl) chlorin (THPC). In another embodiment the photosensitizer 2 3 dihydroxy 5 10 15 20 tetrakis(3 hydroxyphenyl) chlorin (THPD OH) is formulated as a nanoparticle for parenteral administration. Yet in another embodiment preferred photosensitizer is 5 10 15 20 tetrakis(3 hydroxyphenyl) porphyrin (THPP). The formulations can be used for treating hyperptasic and neoplasia conditions inflammatory problems and more specifically to target tumor cells.