Conductimetric determination of some pharmaceutically important 4-quinolone derivatives in dosage forms

A semi-micro titrimetric method is described for the determination of some 4-quinolone derivatives, namely nalidixic acid, ofloxacin, ciprofloxacin hy drochloride and norfloxacin. The method is based on titrating these compoun ds with either sodium hydroxide or tetrabutyl ammonium hydroxide. Alternati vely, silver nitrate was used for the titration of ciproloxacin hydrochlori de. The end point was located conductimetrically. The method allowed the de termination of 1-15 mg of the studied compounds. The method was further app lied successfully to some dosage forms containing these compounds, and the results obtained were: compared favourably with those given with the offici al or reference methods. The proposed method could be also applied to the s imultaneous analysis of mixtures of the studied compounds with other co-for mulated drugs, such as mixture of ciprofloxacin and theophilline and mixtur e of norfloxacin and trimethoprim in their dosage forms. In addition, mixtu re of nalixidic acid and phenazopyridine hydrochloride could be analysed af ter applying an extracting procedure.