Utility of redox reactions for the spectrophotometric determination of tinidazole in pure form and in dosage forms

الملخص EN

Two simple and sensitive spectrophotometric methods for the determination of tinidazole in pure form and in dosage forms are described.

Both methods are based on redox reactions and use Folin-Ciocalteu (Method A) and ferric ferricyanide (Method B) as chromogenic agents.

Method A is based on the measurement of the blue coloured species (λ max : 700 nm) produced when the drug is reacted with Folin- Ciocalteu reagent in alkaline medium, whereas method B involves treating the drug with iron (III) in acid medium and subsequent interaction of iron (II) with ferricyanide to form Prussian blue measurable at 760 nm.

The working conditions of both methods have been optimized.

Regression analysis of Beer’s law plots showed good correlation in the concentration ranges 5-50 and 5-40 µg ml-1 for methods A and B, respectively.

The apparent molar absorptivity and Sandell sensitivity values are calculated to be 5.02 x 103 and 3.36 x 103 l mol-1 cm-1, and 69.15 and 103.45 ng cm-2, respectively, for methods A and B.

Detection and quantification limits for both methods are calculated.

The methods were successfully applied to the determination of tinidazole in bulk drug and its formulations.

Excipients used as additives in formulations did not interfere.

Statistical treatment of the experimental results indicates that the accuracy and precision of the methods are analytically acceptable.

The validity of the methods was evaluated by parallel determination by an established procedure, and by recovery studies.