Role of Alkaloidal Precipitants for the Assay of Itraconazole in Capsules

Abstract

Four simple spectrophotometric methods (A–D) for the assay of itraconazole (ICZ), based on its ability to form water-insoluble complexes, are described. These methods involve the quantitative precipitation of ICZ with phosphomolybdic acid (PMA, method A), ammonium molybdate (AM, method B), iodine (I₂, method C) and tannic acid (TA, method D), followed by the second step of procedure, estimation of either released precipitant from the adduct (precipitate) through acetone addition (methods A, B or D) or the unreacted precipitant in the filtrate (method C) with the chromogenic reagents such as Co(II)-EDTA (for PMA), potassium thiocyanate (PTC, for AM), p-N-methyl aminophenol sulphate—sulphanilamide (PMAP-SA, for I₂) and PMAP-Cr(VI) (for TA). These methods obey Beer's law and give reproducible results. The percentage recoveries are 99.67%.