New Spectrophotometric Methods for Determination of Albendazole in Presence of Cerium as Oxidant and Both Indigo Carmine and Alizarin Red Dyes in Bulk and Dosage Forms

Novel spectrophotometric methods have been developed for the determination of albendazole in bulk, tablet and suspension dosage forms. Solution of albendazole in methanol was oxidized using known excess ceric ammonium nitrate (Ce4+) then the un-reacted amount of Ce4+ was determined using two different dyes, indigo carmine and alizarin red using universal buffer. The reaction showed maximum absorbance at 610 nm for indigo carmine and at 401 nm for alizarin red. Different factors were studied such as type of buffer, dye volume, oxidant volume, time, temperature, organic solvents, and sequence addition. It was found that Beer's law is obeyed in the range of 1.32-7.95 µg mL-1 for albendazole with both dyes with molar absorptivity of 4.69× 103 L.mol-1.cm-1 for indigo carmine and 97.53× 103 L.mol-1.cm-1 for alizarin red. Also the methods showed a high degree of sensitivity in respect of limit of detection which was reported to be as low as 0.24 and 0.35 µg mL-1 in case of indigo carmine and alizarin red, respectively. By applying statistical treatment, it was found that the methods were accurate and precise with low standard deviation values. The methods were then applied for the determination of albendazole in tablet and suspensions with satisfactory results.

Keywords: spectrophotometric; albendazole; ceric ammonium nitrate; indigo carmine; alizarin red.