Spectrophotometric determination of nifedipine via charge-transfer complexes

A simple and sensitive spectrophotometric method for the determination of Nifedipine is described, based on the formation of charge-transfer complex using tetrachloroquinone (chloranil) as Π-acceptor. This complex exhibit intense absorption bands in the electronic spectrum. The molecular ratio of the reactant in the complex was established and the experimental conditions leading to maximum charge-transfer band also studied. The proposed procedure has been applied successfully to pure sample and drug formulation with good accuracy. Beer's Law is obeyed over the concentration range 15,5 - 77,5 mg/100 mL for chloranil. The optimum experimental parameters for colour production with reagent were studied and incorporated into procedure.