Azathioprine Tablets
Action and use
Immunosuppressant.
Definition
Azathioprine Tablets contain Azathioprine.
Content of azathioprine, C9H7N7O2S
92.5 to 107.5% of the stated amount.
Identification
butan-1-ol saturated with 6m ammonia.
The principal spot in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2).
TEST
5-Chloro-1-methyl-4-nitroimidazole and 6-mercaptopurine
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
butan-1-ol saturated with 6m ammonia.
The test is not valid unless the chromatogram obtained with solution (2) shows two clearly separated spots.
Any spot in the chromatogram obtained with solution (1):
corresponding to 6-mercaptopurine in the chromatogram obtained with solution (2) is not more intense than the spot in the chromatogram obtained with solution (3);
any spot corresponding to 5-chloro-1-methyl-4-nitroimidazole in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (4).
Assay
Weigh and powder 20 tablets. Shake a quantity of the powder containing 0.15 g of Azathioprine with 20 mL of dimethyl sulfoxide for 15 minutes and dilute to 500 mL with 0.1m hydrochloric acid. Avoid heating or the use of ultrasound. Filter, dilute 25 mL of the filtrate to 1000 mL with 0.1m hydrochloric acid and measure the absorbance of the resulting solution at the maximum at 280 nm, Appendix II B. Calculate the content of C9H7N7O2S taking 628 as the value of A(1%, 1 cm) at the maximum at 280 nm.
Storage
Azathioprine Tablets should be protected from light.