Iobenguane I-131 is a radioactive therapeutic agent. The drug contains radioactive isotope I-131, which decays by electron emission with a half-life of about 8 days. By the chemical structure, iobenguane is similar to the neurotransmitter norepinephrine and is subject to the same uptake and regulation pathways. After intravenous administration, iobenguane I-131 accumulates within pheochromocytoma and paraganglioma cells, and radiation from the radioactive decay causes cell death and tumor necrosis. Iobenguane I-131 was approved by the FDA for the treatment of adult and pediatric patients with iobenguane scan positive, unresectable, locally advanced or metastatic pheochromocytoma or paraganglioma who require systemic anticancer therapy. Iobenguane I-131 is investigated in clinical trials as a treatment of neuroblastoma, ganglioneuroblastoma and other tumors of neuroendocrinal origin.

Methylparaben (E number E218) is preservative in the food, cosmetic, and pharmaceutical industries. It is completely absorbed through the skin or after ingestion and and it is hydrolyzed to para-hydroxybenzoic acid, and metabolites are rapidly excreted in the urine. Methylparaben is on the FDA generally regarded as safe list.