[Methodological study on the determination of oxiracetam concentration in serum and urine by HPLC]

A method was developed for the determination of oxiracetam concentration in serum and urine by HPLC. Acyclovir was used as an internal standard. The analytical column was a stainless-steel column (30 mm x 4.6 mm ID) filled with 10 microns Bondapak NH2. A mixture of acetonitrile and water (80: 20) as mobile phase was used at a flow rate of 1 ml.min-1. Detection was performed at 210 nm. The retention times were 6.3 min for oxiracetam and 8.1 min for the internal standard. The lower detection limits were 1 microgram.ml-1 for serum and 20 micrograms.ml-1 for urine. The precision and accuracy within-day and day-to-day for both serum and urine samples ranged from 5.0 to 10.7%. The mean recoveries were 99.7 +/- 5.9% and 99.0 +/- 5.6% for human serum and urine, respectively. The results showed that the method is simple, rapid, sensitive, reliable and good enough to be used in studying the clinical pharmacokinetics of oxiracetam.