High Performance Liquid Chromatographic Assay for Adinazolam Mesylate in Rodent Feed Mixtures

Abstract Adinazolam mesylate was recovered from the feed mixtures by repeated extraction with a pH 4 citrate buffer. The pooled extracts were diluted with water when necessary and mixed with an equal volume of an acetonitrile solution of internal standard (naphthalene). After mixing and centrifugation, the clear supernates were separated for chromatography. The chromatography was carried out on a reverse phase column using a mixture of phosphate buffer, acetonitrile and methanol in the volume ratios of 85:40:20 as mobile phase. Adinazolam and the internal standard were eluted from the columns at about 11.7–12 and 15.50–17.5 minutes, respectively. The peak height ratios and adinazolam mesylate concentrations showed excellent linearity (r>0.999). Extracts of blank feed samples did not show interference to the assay. Assay results with satisfactory accuracy and precision were obtained. The methodology was applicable for the assay of the drug-feed mixtures containing 0.02 to 10.0 mg of adinazolam mesylate per...