Objective:To establish a high performance liquid chromatography(HPLC)method for the determination of levofloxacin in the rabbit tibia and bone morrow;to evaluate the release characteristics of levofloxacin in nanoparticles contained levofloxacin degradation-controllable bone repair materials in rabbit local bone tissue and bone marrow. Methods:Different concentrations of levofloxacin were added in blank tibia and bone marrow respectively. Ciprofloxacin was used as an internal standard. Sepax BR-C18(250 mm×4.6 mm 5 μm)column was employed;the mobile phase was:0.01 mol/L potassium dihydrogen phosphate-methanol-0.5 mol/L tetrabutylammonium bromide(75∶25∶4);flow rate was 1.0 ml/min;column temperature was 40 ℃;detection wavelength was 290 nm. Evaluation indexes were linear range

recoveries

extraction recoveries

intra-day precision

inter-day precision

sample stability and accuracy. Results:When the tibia of levofloxacin concentrations in 0.05-300 μg/ml

good linear relationship was achieved(r=0.999);low

medium and high concentrations of three recoveries were(108.81±1.14)%

(96.85±3.64)%

(114.38±0.27)%;the extraction re coveries were(110.92±0.42)%

(110.48±0.97)%

(80.39±0.08)%;intra-day precision RSD were 1.30%

0.23%

5.51%;inter-day precision RSD were as follows:7.09%

3.71%

2.55%

a good sample stability. When the bone marrow levofloxacin concentrations in 0.05-300 μg/ml

a good linear relationship was achieved(r=0.999);low

medium and high concentrations of three recoveries were(91.67±3.73)%

(101.77±0.26)%

(87.72±0.72)%;the extraction recoveries were(102.97±0.81)%

(87.00±0.62)%

(99.97±1.15)%;intra-day precision RSD were 1.49%

1.06%

0.11%;inter-day recision RSD were as follows:5.61%

2.56%

2.37%

a good sample stability. Conclusion :With the advantages of simple

sensitive

stable

high recovery rate

this method is applicable to the detection of distribution of levofloxacin in rabbit local bone tissue in a new bone repair materials.