Biotransformation kinetic of binifibrate and identification of its metabolites

The metabolism of binifibrate was studied in 10,000 g supernatant fractions from rat liver. Binifibrate was found to be completely biotransformed into clofibric acid and nicotinic acid at 60 min from the start of incubation through a series of intermediate products among which glycerol dinicotinate was identified. The biotransformation constant of binifibrate into its different metabolites proved to be 0.11 +/- 0.025 min-1. The formation of clofibric acid follows a first-order kinetic process characterized by its corresponding rate constant (kc), proving to be 0.043 +/- 0.017 min-1. The amount of clofibrate was 0.78 +/- 0.16 mumol/ml, showing that it is not biotransformed later in the incubation mixture. The formation constant of nicotinic acid (kn) was 0.067 +/- 0.020 min-1 and the amount of substance contained in the incubation mixture (0.94 +/- 0.25 mumol/ml shows that it is later biotransformed in the incubation mixture through the previously described metabolic processes.