Bioequivalence of paracetamol and codeine phosphate tablets(II) in healthy volunteers

AIM To study the bioequivalence of paracetamol and codeine phosphate tablets(Ⅱ)test preparation and reference preparation in healthy volunteers.METHODS The plasma concentrations of paracetamol and codeine in 20 healthy male volunteers were determined by LC-MS/MS method after being orally administered with single dose of 600 mg paracetamol and 30 mg codeine test and reference preparations by randomized crossover way.The pharmacokinetic parameters and the relative bioequivalence of the two preparations of paracetamol and codeine were calculated by DAS Ver 2.0 software.RESULTS The main pharmacokinetic parameters of paracetamol reference and test preparations were as follows: ρmax was(9 390.7±1 952.3) and(9 585.9±2116.8) μg·L-1,tmax was(0.94±0.41) and(0.96±0.37) h,t12 was(2.84±0.65) and(2.90±0.60) h,AUC0→t was(37 662.3±10 113.1)and(39 906.8±11 177.6) μg·h·L-1,AUC0→∞ was(40 289.5±11 802.7)and(42 977.4±13 313.5) μg·h·L-1,respectively.The main pharmacokinetic parameters of codeine reference and test preparations were as follows: ρmax was(89.1±35.3)and(83.3±30.6) μg·L-1,tmax was(0.91±0.33)and(1.04±0.53) h,t12 was(2.88±0.55)and(2.69±0.50) h,AUC0→t was(319.7±75.9) and(332.6±82.0) μg·h·L-1,AUC0→∞ was(340.9±82.1) and(352.2±88.5) μg·h·L-1,respectively.The relative bioavailability of paracetamol and codeine was(106.5±13.1)% and(105.6±20.6)%,respectively.CONCLUSION The results show that paracetamol and codeine phosphate tablets(Ⅱ)test preparation and reference preparation are bioequivalent.