Abstract: ABSTRACT OBJECTIVE To develop methods for the determination of metformin and glipizide in human urine and to study the urinary excretions of drugs in healthy Chinese volunteers after single dose administration. METHODS After metformin urine samples were diluted by mobile phase, the supernatant was injected into the system directly by using Lichrospher ODS coLumn with a mobile phase of 3 mmoL/L sodium dodecylsulfate (pH 4)∶acetonitrile (75∶25),and the detection wavelength is 240 nm. Glipizide and IS were extracted by acetic ether after urine acidation, and separated on Lichrospher ODS column using acetonitrile and 0.1% acetic acid (10 mmoL?L-1ammonium acetate) (55∶45) as mobile phase. MS was performed in the selected anion monitoring mode. Ten health Chinese volunteers were treated with single dose of two metformin-glipizide tablets, the metformin and glipizide concentrations in urine were determined by the methods. RESULTS The inter-day and intra-day precision values were below 10%. In 24 h，the accumulation amounts of metformin and glipizide excreted in urine were 102.5 ± 27.3 mg、452.2 ± 191.4 μg, respectively, the accumulated excretion rates were 26.27 % ± 7.0 %, 9.04 % ± 3.83 %, respectively. CONCLUSIONS The assays have been proved to be accurate and sensitive, and can be used in the study of human urinary excretions of glipizide and metformin.

Key words: metformin, glipizide, LC-MS, HPLC, urinary excretion