RESUMO
Simple and sensitive HPLC method for the determination of trimebutine in human plasma was described. For the best separation, a suitable mobile phase consisted of 0.05 M phosphate buffer adjusted to pH 3.5 with phosphoric acid-methanol-isopropanol [32: 58: 10 by volume] was investigated. The mobile phase was prepared to contain 0.006 g% of sodium lauryl sulfate. The drug after extraction from plasma was chromatographed on a C-18 column. Trimebutine and internal st and ard, propyl para-hydroxybenzoate sodium salt [PPB], were detected at 265 nm. Extraction of the drug from plasma was developed to be complete, simple and non-destructive for the active components. The intra- and inter-assay coefficients of variation were less than 5%. The detection limit [signal-to-noise ratio = 3] was 0.5 mug/ml for plasma and the linearity was valid up to 12 mug/ml. The assay was successfully applied to study the bioequivalency of two commercial products containing trimebutine maleate. The tested tables were bioequivalent to the reference tablets