Development and validation of analytical methods for the determination of anti-fungal drug in active pharmaceutical ingredient and other dosage forms

Development and validation of analytical methods for the determination of anti-fungal drug in active pharmaceutical ingredient and other dosage forms

A simple and sensitive extractive spectrophotometric method is proposed for the determination of fluconazole drug, in pure form and in the available dosage forms. The method (A) is based on ion-pair formation between the fluconazole and Mo(V)-thiocyanate inorganic complex in the acidic medium and method (B) is based on ion-pair formation between the fluconazole and Co(II)-tetrathiocyanate inorganic complex in the acidic medium. For method (A), the formed coloured ion-pair is extracted with dichloromethane and absorbance is measured quantitatively with maximum absorption at 470nm. The molar absorptivity and Sandells sensitivity of the coloured species are 0.38x104 L mol-1 cm-1 and 0.8 ng cm-2 respectively. Beers law is obeyed between 4.0 -50.0 ?g mL-1 of fluconazole concentration. For method (B) the formed coloured ion-pair is extracted by using a mixture of (3.5:6.5) n-butanol : dichloromethane and the absorbance is measured quantitatively with maximum absorption at 620nm. The molar absorptivity and Sandells sensitivity of the coloured species are 0.268x104 L mol-1 cm-1 and 0.114 ng cm-2 respectively. Beers law is obeyed between 5.5.0-80 ?g mL-1 of fluconazole concentration. The first order derivative spectrophotometric method is also proposed for the determination of fluconazole in pharmaceutical formulations. The proposed methods are successfully applied for the assay of the fluconazole drug in different dosage forms without any interference from common excipients. The results are in good agreement with those obtained by the official pharmacopeial method. Keywords: Spectrophotometry, fluconazole, ion-pair complex, pharmaceutical preparation, molybdenum thiocyanate, cobalt thiocyanate.

M. Kavitha

Chemistry