Kinetic spectrophotometric methods for the quantitation of triprolidine in bulk and in drug formulations

A kinetic method for the accurate and sensitive determination of triprolidine has been described. The method is based on the alkaline oxidation of triprolidine with KMnO(4). At a fixed time of 20 min, the formed manganate ion is spectrophotometrically measured at 612 nm. The concentration of triprolidine is calculated using the calibration equation for the fixed time method. Beer's law was obeyed from 6 to 40 microg ml(-1) and the R.S.D. (n=10) was 0.97%. Recovery was 99.80%. The method is suitable for quantitative determination of triprolidine in the presence of co-formulated drugs, since pseudoephedrine hydrochloride, which is frequently co-formulated with triprolidine did not interfere with this assay. The intra- and inter-day R.S.D. values indicated the ruggedness of the method. The method has been applied successfully to commercial tablet dosage form. The results obtained agreed with those obtained by the BP method. The determination of triprolidine by the fixed-concentration and rate constant methods is feasible with the calibration equations obtained, but the fixed time method proves to be more applicable.