Spectrophotometric determination of pizotefin maleate in pure form and tablets using π-acceptors
Two simple, quick and sensitive methods were described for the spectrophotometric determination of pizotefin maleate (PZT) either in pure form or pharmaceutical form (tablets). The methods were based on the reaction of pizotefin maleate as ‘n’ electron donor with chloranilic acid (p-CLA) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π-acceptors to give highly coloured radical anion species which were quantitated spectrophotometrically at 533 and 839 nm for chloranilic acid and 7,7,8,8-tetracyanoquinodimethane, respectively. Different experimental conditions for the two methods were optimized. Beer’s law was obeyed in the concentration ranges of 10-160 and 2.0-20 mg mL-1 PZT for p-CLA and TCNQ, respectively with good correlation coefficient of ≥0.9993 and a relative standard deviation (RSD) of ≤ 1.31%. The molar absorptivity, Sandell sensitivity, detection and quantification limits were also reported. The proposed methods were successfully applied for determination of PZT in tablets with good accuracy and precision and without interferences from common additives by applying the standard addition technique. The developed methods have been validated statistically for their accuracy, precision, sensitivity, selectivity, robustness and ruggedness as per ICH guidelines and the results compared favourably with those obtained using the reported method.
KEY WORDS: Pizotefin maleate, Charge transfer complexes, Spectrophotometry, Tablets
Bull. Chem. Soc. Ethiop. 2015, 29(2), 187-197