The Use of Spectrophotometric and Thermodynamic Methods for the Determination of Glibenclamide

A spectrophotometric and thermodynamic method is described for the assay of glibenclamide. The
method involves a charge transfer complexation reaction between glibenclamide with 2,3-Dichloro-
5,6-Dicyano-1,4-benzoquinone (DDQ) to form very intense coloured charge transfer complex having a
stoichiometric ratio of 1:1. The resultant coloured product was analyzed at 474 nm under the
optimized experimental conditions. Over the concentration range of 20-100 μg/ml, Beer - Lambert’s
law was obeyed. The apparent molar absorptivity was calculated and found to be 0.99 × 103 L.mol-
1cm-1. The corresponding Sandell’s sensitivity, Limits of detection and quantification were reported.
Also, the thermodynamic parameters were determined. The proposed method was applied
successfully to the determination of glibenclamide in pure and commercial forms with good average
recovery of 98.24%. Statistical comparison was done using student t-test and f-test at 95% confidence
level.