Development and Validation of Spectrophotometric Determination of Loratadine Through Chargetransfer Complexation With Iodine and Chloranil

Abstract

Two simple, sensitive and inexpensive spectrophotometric methods have been described for the determination of loratadine, an antiallergic drug. The procedure was based on the formation of coloured chargetransfer complexes of loratadine acting as an n-electron donor with iodine acting as σ-acceptor in chloroform (method A) and 2,3,5,6-tetrachloro-1,4-benzoquinone (p-chloranil) acting as π-acceptor in dimethyl sulfoxide (method B). The optimizations of various experimental conditions and the mole ratio were studied. The chargetransfer complexes formed were found to absorb at 399 nm and 528 nm. Beer's law was obeyed for these methods in a concentration range of 6.5-78 mM and 0.2-6 µg ml -1 with correlation coefficients 0.9999 and 0.9993. Application of these methods to the assay of loratadine in tablet form was described and the results were statistically validated. The results of analysis of commercial formulations and the recovery study of the drug suggested that there was no interference from any excipients, which were present in pharmaceutical formulations.