Flucytosine Tablets
Action and use
Antifungal.
Definition
Flucytosine Tablets contain Flucytosine.
Content of flucytosine, C4H4FN3O
92.5 to 107.5% of the stated amount.
Identification
Shake a quantity of the powdered tablets containing 0.5 g of Flucytosine with 100 mL of methanol for 30 minutes, filter and evaporate the filtrate to dryness. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of flucytosine (RS 146).
TESTS
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
1 volume of anhydrous formic acid, 15 volumes of water, 25 volumes of methanol and 60 volumes of ethyl acetate.
The test is not valid unless the chromatogram obtained with solution (3) shows two clearly separated spots.
Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) (0.1%).
Assay
Weigh and powder 20 tablets. To a quantity of the powder containing 0.1 g of Flucytosine add 80 mL of 0.1m hydrochloric acid and shake for 15 minutes. Dilute to 100 mL with 0.1m hydrochloric acid and filter. Dilute 10 mL of the filtrate to 100 mL with 0.1m hydrochloric acid and further dilute 10 mL of the solution to 100 mL with 0.1m hydrochloric acid. Measure the absorbance of the resulting solution at the maximum at 286 nm, Appendix II B. Calculate the content of C4H4FN3O taking 709 as the value of A(1%, 1 cm) at the maximum at 286 nm.
Storage
Flucytosine tablets should be protected from light.