Spectrophotometric Determination Of Amitriptyline By The Method Of Charge-Transfer Complexation With Chloranilic Acid

Abstract

Spectrophotometric technique was employed in the quantitative determination of amitriptyline in its pharmaceutical tablet formulation. The complex produced a purple colour that absorbed maximally at 520 nm and was stable over 10 h. The molar absorbtivity and Sandell\'s sensitivity for the complex were 4666 l mol^-1 cm^-1 and 15 ng/ml respectively. The complexation reaction obeys Beer-Lambert law between 3.134 x 10^-2 M and 3.314 x 10^-1 M that was investigated. Quantitative analysis of three (3) different brands of amitriptyline by the proposed method gave recoveries of A = 97.8 ± RSD 0.81 %; B = 98.7 ± RSD 0.75 % and C = 98.3 ± RSD 0.88 %. Pharmacopoeia method gave corresponding values of 95.5 ± RSD 2.96%; 96.1 ± RSD 2.15 % and 95.15 ± RSD 3.05 % respectively. These results show that the proposed method is more sensitive than the official method. Statistical comparison of these techniques by Student t-test (p > 0.05) however did not suggest any significant difference between them. The simplicity and accuracy of the proposed method means that it could be used for rapid screening of amitriptyline in hospital environment where elaborate and sophisticated equipment may not be readily available.

KEY WORDS: Amitriptyline, chloranilic acid, spectrophotometric analysis

Global Journal of Pure and Applied Sciences Vol.11(2) 2005: 237-240