Simultaneous determination of ranitidine and its metabolites in human plasma and urine by high-performance liquid chromatography.
A sensitive high-performance liquid chromatographic method was developed for the simultaneous determination of ranitidine and its metabolites, ranitidine N-oxide, ranitidine S-oxide and desmethylranitidine, in human plasma and urine. For the plasma analysis, 1-ml plasma samples spiked with phenylpyramidol as the internal standard were extracted at basic pH with acetonitrile-ethyl acetate (3:2, v/v). After evaporation and reconstitution, the samples were chromatographed on a cation-exchange column, with a mobile phase of 0.1 M sodium acetate buffer (pH 5)-acetonitrile-tetrahydrofuran (56.5:36:7.5, v/v) and ultraviolet detection at 320 nm. The extraction recoveries were 99.8, 30.4, 74.2 and 80.2% and the detection limits were 5, 15, 10 and 4 ng/ml for ranitidine, ranitidine N-oxide, ranitidine S-oxide and desmethylranitidine, respectively. For the urine analysis, a simple deproteinization with an equal volume of acetonitrile was satisfactory for sample preparation. The applicability of this method for the pharmacokinetic study of ranitidine following oral administration was demonstrated.
Drug Analysis Division, Department of Medical Sciences, Yod-se, Bangkok.
T
T
Prueksaritanont
N
N
Sittichai
S
S
Prueksaritanont
R
R
Vongsaroj
D000328:Adult; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008297:Male; D011899:Ranitidine / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D013056:Spectrophotometry, Ultraviolet
D011899:Ranitidine