Spectrophotometric Determination of Trimipramine in Tablet Dosage Form via Charge Transfer Complex Formation

Purpose: To develop and validate simple, rapid and sensitive spectrophotometric procedures fordetermination of trimipramine in tablet dosage form. Methods: The methods were based on the interaction of trimipramine as n-electron donor with the σ-acceptor, iodine and various π-acceptors, namely: chloranil (CH), chloranilic acid (ChA), 2,3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ), and 7, 7,8, 8 tetracyanoquinodimethane (TCNQ), to form charge transfer complexes. The complexes obtained were measured spectrophotometrically at 292, 220, 520, 302, and 824 nm for I2, CH, ChA, DDQ, and TCNQ, respectively. Different variables affecting the reaction were carefully studied and optimized. Results: Beer s law was obeyed over the concentration ranges 1 - 5, 5 - 50, 15 - 100, 5- 50, and 10 -75 ppm for I2, CH, ChA, DDQ, and TCNQ respectively, with apparent molar absorptivities of 7.1 times 10^4, 0.3 times10^4, 1.6 times 10^4, 0.26 times 10^4, and 0.1 times 104 l mol^-1cm^-1 respectively. The proposed methods were successfully applied to the determination of trimipramine with good accuracy and precision. Conclusion: The results demonstrated that the developed methods are as accurate, precise and reproducible as the pharmacopeial method. The methods would be valuable for routine application in quality control.