TITLE:
A Novel Spectrophotometric Method for Determination of Gabapentin in Pharmaceutical Formulations Using 2,5-Dihydroxybenzaldehyde
AUTHORS:
Magda S. Saleh, Ahmed K. Youssef, Elham Y. Hashem, Doaa A. Abdel-Kader
KEYWORDS:
Gabapentin, 2, 5-Dihydroxybenzaldehyde, Pharmaceutical Formulations, Spectrophotometric Analysis
JOURNAL NAME:
Computational Chemistry,
Vol.2 No.2,
April
23,
2014
ABSTRACT: A highly simple, rapid, sensitive and selective method is developed for spectrophotometric determination
of gabapentin in pure form as well as in pharmaceutical formulations. The method is
based on the formation of a yellow Schiff base derived from the condensation of gabapentin drug
(1-amino methyl) cyclo hexane acetic acid and 2,5-dihydroxybenzaldehyde (DHBA) exhibiting a
maximum absorbance at 445 nm. The composition, molar absorptivity and effect of different excipient
have been determined spectrophotometrically. Under optimized experimental conditions,
Beer’s law is obeyed in the concentration range 2.57 - 37.25 μg/ml. The method is validated with
respect to accuracy, precision, limit of detection and limit of quantification. The Sandell sensitivity,
correlation coefficient and regression equation are calculated. The equilibrium constant and free
energy change using Benesi-Hildebrand plot are also determined. The Schiff base derived from
condensation of gabapentin with DHBA is also synthesized and characterized. The condensation
reaction mechanism has been proposed.