A Sensitive Gas Chromatographic Assay for the Determination of Serum Viloxazine Concentration Using a Nitrogenhyphen;Phosphorushyphen;Selective Detector

摘要

A gas-liquid chromatographic procedure for measuring the serum levels of the antidepressant viloxazine is described. The drug and the internal standard imipramine (IMI) are extracted from 1 ml serum. The method involves a three-step extraction, derivatization of viloxazine with acetic anhydride, and injection into a gas chromatograph equipped with a nitrogen-phosphorus-selective detector. The retention times for IMI and viloxazine were 4.7 and 6.1 min, respectively. The standard curves were linear over the 100minus; to 2,000-ng/ml range. The recovery averaged 64.5percnt; and the lowest detection limit was 80 ng/ml. The within-run and day-to-day coefficients of variations were 11.9 and 12.5percnt;, respectively, at 250 ng/ml, and 8.9 and 9.2percnt;, respectively, at 1,500 ng/ml. The method is adequate both for single-dose pharmacokinetic studies and for monitoring serum viloxazine levels in chronically treated patients.