Pharmacokinetics of compound paracetamol tablets (II) in healthy volunteers

Objective: To establish a HPLC method for the assessment of the pharmacokinetics of compound paracetamol tablets (Ⅱ) (each containing paracetamol 250 mg, propyphenazone 150 mg and caffeine 50 mg). Methods: 20 healthy male Chinese volunteers received a single oral dose of the two tablets. Plasma samples were collected at certain time-points in 24 hours post the administration of the tablets to measure concentrations of each component in the tablets by HPLC. The HPLC analysis was conducted via a system consisted of Phenomenex Phenyl-BDS column (250 mm×4. 6 mm,5μm) , a gradient eluate of methanol and acetate buffer and a detection waVelength at 260 nm. Results: The main pharma-cokinetic parameters of paracetanol, propyphenazone and caffeine were as followed: Cmax(3. 57±0. 82) vs. (2.50±0.69) vs. (1. 23±0. 33)μg·mL-1; Tmax(0. 43±0.23) vs. (0.54±0.27) vs. (0.45±0.23)h; t1/2(λZ) (4.27±0.76) vs. (2. 01±0. 44) vs. (5. 49±1. 44)h; MRT(5. 05±1. 06) vs. (2.94±0. 58) vs. (7. 85±1. 88) h; AUC0-24h(13. 17±33.27)vs. (6. 37±1. 80) vs. (8.78±3.20) h·μg·mL-1; CL/F (41.64±325.62) vs. (53.68±17.45) vs. (13. 15±4.91) L·h-1 and V/F (166. 57±109. 80) vs. (106. 86±21. 42) vs. (87. 51±15. 06)L, respectively. Conclusion: This established sensitive and reliable HPLC method is applied in the investigations of pharmacokinetics of the compound paracetamol tablets (Ⅱ).