Batch and Reverse-Flow Injection Spectrophotometric Determination of Hyoscine Butylbromide in Pharmaceutical Formulations

Hyoscine butyl bromide (HBB), also known as scopolamine butyl bromide, is an anticholinergic medication used to treat bladder spasms, renal colic, esophageal spasms, and crampy abdominal pain. A fast and simple spectrophotometric approach is developed for the determination of hyoscine butyl bromide in pure and pharmaceutical formulations using batch and flow injection methods. The proposed approach is based on the reduction of ferrate ion to ferrous ion by HBB and the subsequent formation of excess Fe(III)-thiocyanate complex which gave maximum absorbance at ۴۷۸ nm. The experimental conditions of both methods for the assay were studied and optimized. The absorbance was found to decrease linearly with the drug concentration to give a calibration curve which obeys Beer’s law in the range of ۰.۵-۲۰۰, and ۵.۰-۲۰۰ μg/mL with a linear regression coefficient of ۰.۹۹۶۴, and ۰.۹۹۰۹ with detection limits of ۱.۴۰, and ۲.۱۰ µg/mL for both batch and rFIA methods, respectively. The proposed approaches were successively applied for the determination of the studied drugs in their different pharmaceutical dosage forms and gave an excellent per cent of recovery compared with the official international pharmacopoeia method.