Sensitive Bromatometric Assay Methods for Finasteride in Pharmaceuticals

The document presented three sensitive spectrophotometric methods for determining finasteride in bulk and tablet forms using bromate-bromide reagent and dyes such as methyl orange, indigocarmine, and thymol blue. These methods involved adding an excess of bromate-bromide reagent to finasteride in an acid medium, followed by measuring the unreacted bromine with the dyes at specific wavelengths: 520 nm for methyl orange (method A), 610 nm for indigocarmine (method B), and 550 nm for thymol blue (method C). The absorbance increased linearly with finasteride concentration, adhering to Beer’s law within specific ranges for each method: 0.25-2.0 μg/mL for method A, 0.5-6.0 μg/mL for method B, and 1-12 μg/mL for method C.