ELECTROCHEMICAL REDUCTION OF FLUNITRAZEPAM AND ITS DETERMINATION IN PHARMACEUTICAL DOSAGE FORMS BY DIFFERENTIAL-PULSE POLAROGRAPHY

A simple, rapid differential pulse polarographic method has been devel oped for the determination of flunitrazepam in pharmaceutical dosage f orms using universal buffers of pH 2-6. The substance is extracted fro nt the dosage forms with dimethylformanide, an appropriate buffer of s elected pH is added to an aliquot and the solution then polarographed at dropping mercury electrode vs SCE. The electrochemical reduction be haviour of flunitrazepam has been studied by employing d.c. polarograp hy, cyclic voltammetry, a.c. polarography and differential pulse polar ography using universal buffers of pH 2-12. The two-step reduction wav e/peak observed is found to be irreversible and diffusion-controlled. Kinetic parameters a re evaluated and reduction mechanism is proposed. The standard addition method provides results as satisfactory as thos e obtained with the use of a calibration graph.