POLAROGRAPHIC-BEHAVIOR AND DETERMINATION OF NORFLOXACIN IN TABLETS

The direct current (dc) and differential pulse (dp) polarographic redu ction of the antibacterial drug norfloxacin has been studied in variou s base electrolytes at different pH values in the presence of dimethyl formamide. Only one reduction wave in the range -0.95 to -1.05 V was observed in strongly acidic medium (pH < 1). Using a base electrolyte of pH greater than or equal to 7.5, two well defined irreversible wave s were observed in the ranges of -1.48 to -1.67 V (wave C) and -1.79 t o -1.93 V (wave D) for norfloxacin concentrations of 1 x 10(-4) M. The se potential limits showed little shifts on both sides with norfloxaci n concentration. At pH greater than or equal to 10, only wave D has be en observed, but all waves disappeared completely in 0.1 M NaOH. In ad dition, two ill-defined waves appeared in the range -0.06 to -0.42 V w ithin the pH range 6.5-8.5 for norfloxacin concentrations > 5 x 10(-5) M. The single dp wave which appeared in 2 M HCl and the dp wave C whi ch appeared in the other base electrolytes showed a useful rectilinear relationship between concentration and wave heights from 32 to > 560 mu g ml(-1) norfloxacin. These two dp waves have been utilized for det ermination of norfloxacin in Noroxin tablets with good recoveries. The polarographic behaviour of norfloxacin has been compared to that of n alidixic acid which has been also determined successfully in Negram ta blets as the individual component and in the presence of norfloxacin a s an interferent.