RESUMEN
OBJECTIVE To develop a high-performance liquid chromatographic (HPLC) method for determination of linezolid in human serum, cerebrospinal fluid (CSF) and pancreatic juice. METHODS: With risperidone as internal standard, samples were extracted by methyl tert-butyl ether-repropanol=90:10 (V/V) after added 0.1 mol·L-1 NaOH, then seperated on a Shima-pack CLC-ODS-C18 (6.0 mm ×150 mm, 5 μm) column with mobile phase consisted of methanol-acetonitrile-phosphate buffer solution (0.02 mol·L-1 KH2PO4, PH value was adjusted to about 3.5 by H3PO4)=20:16:64(V/V/V) with a flow rate of 1.0 mL·min-1 at 35℃. Fhe detection wavelength was set at 254 nm. RESULTS: For serum, the linear range of linezolid was from 0.25 to 40.0 mg·L-1 (r=0.999 9). For the three check samples (0.8, 8.0, 25.0 mg·L-1): the intra-run and inter-run RSDs were 1.64%-2.38% (n=5) and 4.53%-6.34% (n=5) respectively, the mean method recoveries and extraction recoveries were 93.781%-97.393% (n=5) and 72.318%-73.442% (n=5) respectively. For cerebrospinal fluid, the linear range of linezolid was from 0.1 to 20.0 mg·L-1 (r=0.999 3). For the three check samples (0.2, 2.0, 15.0 mg·L-1): the intra-run and inter-run RSDs were 3.84%-4.83% (n=5) and 6.04%-8.16% (n=5) respectively, the mean method recoveries and extraction recoveries were 106.910%-110.971% (n=5) and 73.226%-80.603% (n=5) respectively. For pancreatic juice, the linear range of linezolid was from 0.1 to 20.0 mg·L-1 (r=0.999 4). For the three check samples (0.2, 2.0, 15.0 mg·L-1); the intra-run and inter-run RSDs were 2.96%-5.30% (n=5) and 4.68%-6.40% (n=5) respectively, the mean method recoveries and extraction recoveries were 97.178%-105.072% (n=5) and 73.333%-76.010% (n=5) respectively. The mean extraction recoveries of IS were more than 87.00%. CONCLUSION: The method is sensitive, simple and accuracy, and it can be used for clinical study, espicially used in the patient with drag combination.