Methotrexate Disodium Tetrahydrate and its Impurities

Methotrexate Disodium Tetrahydrate, formerly known as amethopterin, is a chemotherapy agent and immune-system suppressant. It is used to treat cancer, autoimmune diseases, and ectopic pregnancies. Reference standards of Methotrexate Disodium Tetrahydrate API, and its pharmacopeial, non pharmacopeial impurities, and stable isotopes are listed below.