Cyclosporine, USP (syn: Cyclosporin,Cyclosporin A) is a natural product and cyclic polypeptide derived from fungi. It is a macrolide with potent immunosuppressive properties. Cyclosporine was isolated in 1971 from the soil fungus Tolypocladium inflatum (Sandoz, now Novartis), and the Norwegian strain is currently used for mass production of this compound. Its immunosuppressive properties were discovered in 1971 via a screening test (Sandoz). Cyclosporine metabolites include Cyclosporin B, D, E, H, and L. Cyclosporine, USP is soluble in DMSO and ethanol. It has very poor water solubility.
