Three simple visible spectrophotometric methods for the assay of cetirizine

Three simple and sensitive spectrophotometric methods (A-C) for the assay of cetirizine (as dihydrochloride, CET) are proposed. Methods A and B are based on the formation of ion-association complex involving carboxylic acid group of CET and the basic dyes, safranin-O (SFN-O, method A), methylene blue (MB, method B). Method C is based on the involvement of tertiary amino group in drug with α,γ-aconitic anhydride (dehydration product of citric acid-acetic anhydride) as coloured internal salt. The methods are suitable for the assay of cetirizine in pharmaceutical formulations.