Estimation of acetorphan in pharmaceutical dosage forms by derivative spectrophotometry and liquid chromatographic methods

Two simple and accurate methods of analysis to determine Acetorphan (ACT) in pharmaceutical dosage forms were developed using first-derivative spectrophotometry and reversed-phase liquid chromatography (LC). ACT was quantified using the first-derivative response at 241.0 nm in spectra of its solution in methanol. The calibrationcurve was linear [correlation coefficient (r) = 0.999] in the concentration range of 10.0–100.0 μg/ml. In the LC method, analysis was performed on a Hypersil ODS-C18 column with 5 μm particle size using the mobile phase methanol-water (80 + 20; v/v), at a flow rate of 1.0 ml/min. Measurement was made at a wavelength of 232 nmand the retention time was 5.358 min. The calibration curve was linear (r = 0.999) in the concentration range of 10.0–500.0 μg/ml. Both methods were validated by following the analytical performance parameters suggested by the International Conference on Harmonization. All validation parameters were within the acceptable range. The developed methods were successfully applied to the estimation of ACT in pharmaceutical dosage forms.