Determination of Bisoprolol Fumarate by Spectrophotography Based on Charge Transfer Reaction

In a medium of alcohol-ketone (3+7) mixture,bisoprolol fumarate was made to react with 7,7,8,8-tetracyanoquinodimethane at 35 ℃ for 30 min to form a 1∶1 charge-transfer complex,having its constant of 4.8×103 and its absorption maximum at the wavelength of 845 nm with its apparent molar absorptivity of 5.37×104L·mol-1·cm-1.Linear relationship was found between values of absorbancy and mass concentration of bisoprolol fumarate in the range of 2.0-14 mg·L-1.RSD (n=6) was found to be 1.5%.The method was applied to the determination of bisoprolol fumarate in its tablets and capsules,giving results in agreement with those obtained by the method given in pharmacopoeia.Values of recovery found by the standard addition method were over 99.0%.