Description

Yellow to orange brown crystalline powder

Biochemistry

Methotrexate is an antimetabolite. It is an inhibitor of dihydrofolate reductase. MTX acts by

altering the body's use of folic acid (a vitamin), which is needed for cell growth. It is

suspected that this interference with folic acid is an important reason for methotrexate's

benefit in rheumatoid arthritis.

Solubility

MTX is practically insoluble in water. It is sparingly soluble in 0.01 M NaOH pH 10.0,

(0.25 g/100 g 0.01 M NaOH (22°C)). Ultrasonication may be used to improve dissolution.

HPLC Conditions

column

Waters Spherisorb S5-ODS1

eluant

10 mM Na2HPO4 pH 6.0 / Methanol (19:1)

flow rate

1 ml/min

wavelength

254 nm

solution

1 mg/ml 0.01 M NaOH

Purity: HPLC

>98.5%. Related substances are N-methylfolic acid, 4-aminofolic acid, 2,4-diami0-

methylpteroic acid and 10-methylpteroic acid.

Stability

Methotrexate powder is stable at room temperature for at least 3 months. It is hygroscopic.

A 1 mM solution of MTX in 0.01 M NaOH is very stable. HPLC analysis of the 1 mM solution

after 7 days at room temperature showed no degradation.

Storage

Keep the powder dry in amber vials at –20°C or colder. Methotrexate can be transported

without the use of dry ice.

Uses

MTX was first developed to treat certain types of cancer. It is routinely used at high doses

as a cancer therapy and is also used at much lower doses to treat neoplastic diseases,

severe psoriasis, Crohn's disease and adult rheumatoid arthritis. Our product is sold for

laboratory use only.

Precautions

Highly Toxic. Use Special Handling precautions. Avoid inhalation and skin contact.

Side effects to the use of this drug may include suppression of bone marrow production of

blood cells, hepatitis, and others.

References

"Taber's Cyclopedic Medical Dictionary", Copyright © 2001 by F. A. Davis Co., Phil., PA.