PHARMACOKINETIC STUDIES OF RIFAPENTINE

The present paper reports the pharmacokinetic studies of rifapentine in 3 monkeys and in 12 healthy volunteers. The plasma protein binding rate of DL-473 is 90.1% by means of bioassay and it is not correlated with the drug concentration in plasma in our experimental conditions. The relationship between the logarithm of percentage of free DL-473 in plasma and plasma concentration is linear. An oral dose of 15mg/kg of DL-473 was given to monkeys. The pharmacokinetic parameters for monkeys were: C_(max) 11.39±3.54μg/ml, t_(max) 12.63±3.34h, t_(1/_2) 15.41±1.57h, k 0.0453±0.0049h~(-1), t(_1/_2)α 4.76±1.81h, k_ 0.1742±0.0975h~(-1), AUC 429.13±158.73μg·h/ml. The healthy volunteers were given orally a dose of 4mg/kg of DL-473. The pharmacokinetic parameters calculated were C_(max) 4.84±1.16μg/ml, t_(max) 6.94±2.15h, t_(1/_2) 17.56±5.39h, k 0.0432±0.0150h~(-1), t_(1/_2)α 16.7±0.71 h, k_a 0.5084±0.0297h~(-1), AUC 154.55±51.01 μg·h/ml.