Quantitation of 5-Flucytosine in capsules using high-pressure liquid chromatography

A stability-indicating reversed phase HPLC method for the quantitation of 5-flucytosine in capsules (the only dosage form available) has been developed. The method requires the use of a mobile phase without any counterion and the samples can be assayed at room temperature. The method is simple, reproducible, precise and accurate with percent relative standard deviation of 0.77 based on 6 readings. There was no interference from the excipients present in capsules and from fluorouracil (the major product of decomposition of 5-flucytosine). The recovery of 5-flucytosine from the synthetic mixtures was quantitative. A simple extraction procedure for 5-flucytosine from the capsules has been developed.