Compositions containing conjugates containing phthalocyanine pigments are provided, the compositions include compositions containing stabilizers such as nonionic surfactants and / or protective agents. In some aspects, the composition reduces agglomeration of the conjugate due to agitation, temperature exposure, and / or pH. Also provided are products containing compositions containing said conjugates and methods for their administration to subjects for photoimmunotherapy. In some embodiments, the phthalocyanine pigment conjugate is conjugated to a targeting molecule, eg, an antibody, that targets the conjugate to a cell or pathogen, such as by binding to a cell surface protein.
