STUDY ON PHARMACOKINETICS AND RELATIVE BIOAVAILABILITY OFDOMESTIC CONTROLLED-RELEASE THEOPHYLLINE TABLETAFTER SINGLE AND MULTIPLE DOES ORAL

HPLC method was used to study the pharmacokinetics and relative bioavailability ofdomestic controlled - release theophylline tablet (DCRTT) and imported controlled - release theophylline capsule (theovent) in 11 healthy volunteers, Our result indicated that the pharmacokinetic parameters for DCRTTwere: T1/2Ke= 14. 07 ± 1.32 h, T1/2Ka= 1.26 ± 0.14 h, V / F(c) =46.2 ± 9.25 1, Cmax = 4. 21 ± 0. 53 mg/l, AUC = 108.6±17. 97 mg· h· 1-1, Relative bioavailability was 0. 844 compared with theovent and the execretion rate of parent drug in urine was 9. 7% within 24 h; for the theovent were: T1/2Ke=9. 89 ± 0.62h, T1/2Ka= 0.52±0.08 h, V / F(c) =27.8± 6.71, Cmax = 7.64±1.21 mg/l, AUC = 128.7 ±25.80 mg · h-1·L-1.The steady - state pharmacokinetics of DCRTT and theovent were investigated in 9 asthma or COPD patients. The result showed that flutuation rate of DCRTT in range of effecting concentration was smaller than that of theovent(P0. 5) .