Compositions, which are stable in storage, and a method of production of pharmaceutical based nanoparticulate formulations for photodynamic therapy comprising a hydrophobic photosensitizer, human serum albumin (HSA) and stabilizing agent are provided. These nanoparticulate formulations provide therapeutically effective amounts of photosensitizer (PS) for parenteral administration. In particular, tetrapyrrole derivatives can be used as photosensitizers whose efficacy and safety are enhanced by such nanoparticulate formulations. A method of preparing the HSA-based nanoparticles under sterile conditions is also provided. In one of the preferred embodiments of the present invention temoporfin, a hydrophobic PS, is formulated as a nanoparticle for parenteral administration. The formulations are useful for treating hyperplasic and neoplasic conditions, inflammatory problems, and more specifically to target tumor cells.