Determination of fenoverine, a modulator of smooth muscle motility, in capsules and in human plasma: application to dosage form stability and a pilot study in humans

Fenoverine is a novel, potent, musculotropic, spasmolytic agent that affects primarily the gastrointestinal tract, bile duct, and female genital organs. A simple, specific, and accurate HPLC method was developed for the determination of fenoverine in capsules and plasma. This method has been successfully applied to stability studies of fenoverine capsules and to a pilot study in a normal, healthy volunteer following oral administration of fenoverine. For the determination of fenoverine in capsules, a Nucleosil 5-micron CN column, with acetonitrile:0.1 M ammonium acetate (60:40) as mobile phase and detection at 254 nm, was employed. The mean correlation coefficient of the calibration curve (n = 6) for the assay was 0.9999 over a concentration range of 24.6 to 147.6 micrograms/mL of fenoverine standard solutions. Fenoverine did not decompose significantly at 4, 45, 55, and 65 degrees C for 3 months. The mean correlation coefficients of within-day and between-day calibration curves were 0.9995 and 0.9999, respectively, over a range of 10 to 1000 ng/mL of fenoverine in plasma. The limit of detection was 10 ng in plasma.