Identification and quantitation of impurities in methotrexate.
The impurities in bulk, commercial, and investigational methotrexate samples were chromatographically separated by gradient elution from a diethylaminoethylcellulose column. Besides the already known impurities in the bulk and commercial samples, two other impurities, 4-amino-N10-methylpteroyl-N-methylglutamine and 2,4-di-amino-N10-methylpteramide, were identified. A new batch of methotrexate, synthesized for the National Cancer Institute for investigational use only, showed a different spectrum of impurities. The purity of all methotrexate samples studied was about 80% calculated on an anhydrous basis.
D055598:Chemical Phenomena; D002621:Chemistry; D002848:Chromatography, DEAE-Cellulose; D004340:Drug Contamination; D008727:Methotrexate / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet
D008727:Methotrexate