Purpose: To develop simple,
sensitive and economical methods for the determination
of (KZ) in both pure samples and pharmaceutical
formulations.
Methods: The first method (A) was
based on the oxidation of the studied drug by a known
excess of cerium (IV) as an oxidizing agent and
subsequent determination of unreacted oxidant by
reacting it with indigo carmine (IN) dye. The second
method (B) involved potassium permanganate as oxidant
and methylene blue (MB) as dye. Spectrophotometry was
used to determine the residual amount of the dyes by
measuring the absorbance of the two dyes at 610 and 660
nm, respectively. Comparison was made with the British
Pharmacopoeia 1998 method.
Results: Linear calibration graphs
were obtained at 4 - 30 and 5 - 35 µg/ml for the two
methods at 610 and 660 nm, respectively. The regression
equation was Y = 0.01X + 0.133, (R2 = 0.996,
RSD = 78 % and limit of detection (LOD) of µg/ml for
method A. For the second method (B), it was Y = 0.008X +
0.039, (R2 = 0.995), RSD = 0.95 % and LOD =
2.3 µg/ml. The proposed methods were successfully
applied to the determination of KZ in pharmaceutical
formulations.
Conclusion: The results demonstrate
that the methods are as accurate and reproducible as
official methods.
Keywords: Ketoconazole,
Spectrophotometry, Cerium, Permanganate, Indigo carmine,
Methylene blue.
