Abstract: The pharmacokinetics of morphine sulphate was studied in 10 Chinese healthy volunteers after a single oral dose. Blood samples were collected before and after administration of controlled release tablets (CRMS, 30 mg) and immediate release tablets (IRMS, 20 mg). The plasma concentration of morphine was determined by GC MS. The pharmacokinetic parameters of controlled release tablets and immediate release tablets were calculated: Cmax was 19.38±3.80 and 21.27±6.21 ng/ml, tmax was 2.36 ±0.37 h and 0.56±0.16 h, t1/2β was 3.53±0.87 and 3.03±0.74 h, AUC was 145.15±17.65 and 93.08±16.65 ng/ml, respectively. The steady state plasma concentration of morphine sulphate in cancer patients after multiple doses was achieved, Cmax of CRMS and IRMS was 27.43±0.33 ng/ml and 22.68±0.16 ng/ml, Cmin of CRMS and IRMS was 19.45±1.44 ng/ml and 18.14±0.49 ng/ml, respectively.

Key words: Controlled release morphine sulphate tablet, Immediate release morphine sulphate tablet, Pharmacokinetics, Single dose, Multiple doses, GC-MS