Spectrophotometric determination of bisoprolol in pharmaceutical preparations by charge transfer reactions

A simple, rapid and sensitive method for the spectrophotometric determination, of bisoprolol was developed. The proposed methods were based on the charge-transfer reactions of bisoprolol, as n-electron donor, with 7,7,8,8-tetracyanoqumodimethane (TCNQ) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as ??-acceptors to give highly colored complexes. The proposed methods were validated according to the ICH guidelines with respect to linearity, limit of detection, limit of quantification, accuracy, precision, recovery and specificity. Beer??s law is obeyed over the concentration ranges of 10?C60 and 10?C80 ??g/mL bisoprolol with TCNQ and DDQ, respectively. The proposed methods were successfully applied to the assay of bisoprolol in pharmaceutical preparations.