F. Belal et al., Conductimetric determination of some pharmaceutically important 4-quinolone derivatives in dosage forms, CHEM ANAL, 44(4), 1999, pp. 763-772
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.