7, 7, 8, 8-Tetracyanoquinodimethane (TCNQ), 2,3-Dichloro-5,6-Dicyano-1,4-Benzoquinone (DDQ) and Tetracyanoethylene (TCNE) Reagents for the Photometric Determination of Sumatriptan and Zolmitriptan in Pure and Dosage Forms

Simple and sensitive spectophotometric method for determination of sumatriptan (Sum.) and zolmitriptan (Zol.) in pure form and in dosage form has been developed. The charge transfer (CT) reactions between sumatriptan and zolmitriptan as n-electron donor and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), 7,7,8,8-tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) as π-acceptors have been spectrophotometrically studied. The absorbance is measured at λ_max = 459, 843 and 415 for DDQ, TCNQ and TCNE, respectively. The optimum experimental conditions for these CT reactions have been studied carefully. Beer's law is obeyed in the range of 10–80 μg/ml, 10–50 μg/ml and 10–40 μg/ml for DDQ, TCNQ and TCNE respectively with zolmitriptan drug and in range of 10–100 μg/ml,10100 μg/ml and 10–70 μg/ml for DDQ, TCNQ and TCNE respectively with sumatriptan drug. Sandell's sensitivity is calculated. Relative standard deviations were obtained for five replicates of the cited drugs with the mentioned reagents. The results obtained by the three reagents with the two drugs are comparable with those obtained by reported methods in raw materials and in dosage forms. The proposed methods are applied successfully for the determination of the drugs in pure form and in commercial dosage forms.