7-Hydroxymethotrexate is a phase I metabolite of MTX, which is converted by hepatic aldehyde oxidases. Elimination of 7-hydroxy MTX is associated with the multi-drug transporters Abcc2, Abcc3, and Abcg2 in transgenic mouse models. It and the parent compound rapidly accumulate when all three transporters are absent.2 Formulations containing methotrexate have been used in the treatment of cancer, autoimmune diseases, ectopic pregnancy, and for the induction of medical abortions. Various methods have been described to quantify 7-hydroxy MTX levels during cancer therapy to avoid toxicity.

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.