Mass fragmentographic determination of ferulic acid in plasma after oral administration of .GAMMA.-oryzanol.

Abstract

A mass fragmentographic method for the quantitative determination of ferulic acid, a main metabolite of .gamma.-oryzanol in rabbit and dog plasma, was developed. After its isolation by Amberlite XAD-2 chromatography and by solvent extraction, ferulic acid was converted to the heptafluorobutyryl ethyl ester derivative and analyzed by using 4-hydroxy-3-trideuteromethoxycinnamic acid (ferulic acid-d3) as an internal standard. The recovery of ferulic acid from plasma samples was 100.5 .+-. 4.5% (n = 20) in the range of 5.0-150.0 ng/ml plasma. .gamma.-Oryzanol was administered orally to rabbits and dogs at doses of 25, 50 and 100 mg/kg body wt as a solution of sesame oil, and then the plasma concentrations of ferulic acid were determined by mass fragmentography. A good correlation between the administered dose of .gamma.-oryzanol and the area under the concentration curve (AUC) of ferulic acid was obtained in both animals; the AUC of ferulic acid may be used as an index for estimating the extent of gastrointestinal absorption of .gamma.-oryzanol.