Abstract: AIM: To develop a specific, sensitive, and accurate HPLC method to measure uric acid, xanthine and hypoxanthine concentrations in human serum.METHODS: Agilent ZORBAX SB-Aq column coupled with a ZORBAX-Extend C₁₈ guard column was employed. The mobile phase consisted of methanol/ 47 mmol/L KH₂PO₄ solution and the flow rate was 1.0 mL/min. The detection wavelength was 260 nm.RESULTS: Good linearity of uric acid, xanthine, hypoxanthine in human serum were (1.667-166.667)×10³ ng/mL(r=0.9995), (0.033-3.338)×10³ ng/mL(r=0.9994), (0.033-3.338)×10³ ng/mL (r=0.9996) , respectively. Intra- and inter-day validation were both less than 15%.CONCLUSION: A rapid, accurate and specific method was developed and validated for the determination of uric acid, xanthine and hypoxanthine in human serum. It was suitable for the pharmacodynamic studies of febuxostat.

Key words: Human serum, Uric acid, Xanthine, Hypoxanthine, HPLC-UV, Febuxostat