A simple high-performance liquid chromatography （HPLC） method was established and subsequently used to study the pharmacokinetics of biapenem in healthy volunteers. Chromatography separation was carried out using a C18 reverse-phase column with an isocratic mobile phase consisting of 0.05 M ammonium acetate-methanol, either for plasma （94：6, v/v, and flow rate 1.0 mL/min） or for urine samples （97.5：2.5, v/v, flow rate 1.5 mL/min）. The UV detector was set at 300 nm. The assay was linear over the range of 0.25 mg/L-50 mg/L for plasma samples and 0.50 mg/L-200 mg/L for urine samples. The intra-day and inter-day RSD values were lower than 2.8% and 4.6%, respectively, for biapenem in plasma, 2.4% and 2.5%, respectively, for biapenem in urine. Biapenem was stable at room temperature for up to 6 h in plasma and 8 h in urine when MOPS was added immediately after sample collection. An intravenous single dose of 600 mg biapenem was administered to 12 healthy male volunteers. The pharmacokinetic parameters were calculated by Winnonlin with a noncompartment model. The pharmacokinetic parameters were obtained as following： Cmax 37±6 mg/L, t1/2 1.27±0.21 h, AUC0-8h 56±8 mg/L/h, and AUC0-∞57±8 mg/L/h. The accumulated urine excretion rate in 24 h was 58%±5%. The established HPLC method was validated and suitable for the pharmacokinetic study of biapenem.
