SPL Set ID: f93d9408-7b3f-b423-e053-6294a90a31ec

Azathioprine, an immunosuppressive antimetabolite, is available in tablet form for oral administration. Each scored tablet contains 50 mg, 75 mg or 100 mg azathioprine, USP and the inactive ingredients anhydrous lactose, magnesium stearate, povidone, pregelatinized starch (corn starch), and stearic acid. Azathioprine is chemically 1 H -Purine, 6-[(1-methyl-4-nitro-1 H -imidazol-5-yl)thio]-. The structural formula of azathioprine is: It is an imidazolyl derivative of 6-mercaptopurine and many of its biological effects are similar to those of the parent compound. Azathioprine, USP is insoluble in water, but may be dissolved with addition of one molar equivalent of alkali. Azathioprine, USP is stable in solution at neutral or acid pH but hydrolysis to mercaptopurine occurs in excess sodium hydroxide (0.1N), especially on warming. Conversion to mercaptopurine also occurs in the presence of sulfhydryl compounds such as cysteine, glutathione and hydrogen sulfide. 1