Determination and assay validation of the bioactive sesquiterpene lactone xanthatin isolated from Xanthium...

This study describes the development and validation of a method for quantification of the antiulcer experimental drug xanthatin in tablets by capillary electrophoresis (CE). Solid oral dosage forms based on xanthatin were designed and assayed on rats. A CE methodology was developed; the parameters evaluated were: background electrolyte composition, concentration and pH, applied voltage and sample preparation. The method was validated in terms of range of linearity, limits of detection (LOD) and quantification (LOQ), accuracy, precision and selectivity and then applied to the pharmaceutical dosage forms. Xanthatin determination was carried out in less than 3 min with a 20 mM sodium tetraborate buffer, pH 9.20. Drug concentration per tablet found was 2.97 +/- 0.2 mg. Calibration plots were linear over at least three orders of magnitude of analyte concentrations, LOD and LOQ were 7.6 and 26 microg mL(-1) respectively. For accuracy evaluation a recovery test was performed, the values being better than 98.6%. With respect to precision, the results obtained were better than 1.02 RSD% (repeatability) and 1.54% (intermediate precision). After the manufacturing process the resulting tablets were biologically active. The methodology developed is useful, simple and rapid for xanthatin determination in tablets.