Stability and bioavailability of a flucytosine suspension

Abstract

Abstract The stability and bioavailability of a suspension of flucytosine was evaluated. There was found to be no change in the flucytosine content of the suspension over a three month period. A shelf life of at least three months could be given to suspensions made by large scale dispensing. The bioavailability of the suspension was compared with that of commercially available tablets in eight healthy male volunteers. A single dose (2g) of tablets was administered to each volunteer and urine samples were collected over a 24 hour period. After a washout period of one week, the procedure was repeated using the suspension (2g/20ml). The bioavailability of the suspension relative to commercially available tablets was 80.7 per cent. The high performance liquid chromatography (HPLC) method used was found to give consistent results for tablet and suspension assays and for urine analysis (relative standard deviation 1.8 per cent, correlation coefficient r = 0.996). Where patients have impaired swallowing reflexes or few accessible sites for venepuncture, flucytosine suspension may have several advantages when large doses (10–15g/day) need to be administered.