Isoindole based fluorophore for the sensitive fluorimetric determination of isobutyl gamma aminobutyric acid

摘要

The present work deals with the development and validation of a selective and highly sensitive spectrofluorimetric method for determination of 3-isobutyl gamma amino butyric acid (3-isobutyl GABA). The drug is selectively condensed with o-phthalaldehyde in presence of 2-mercaptoethanol to form a highly fluorescent isoindole derivative. The fluorescent intensity of the obtained fluorophore was monitored at 431 nm (lambda(ex)= 335 nm). The influence of reaction conditions was investigated in order to enhance the sensitivity of the proposed procedure. At the optimized reaction condition the fluorescence intensity was found to be in linear relationship with drug concentration in the range of 0.025 0.125 mu g ml(-1). The quantitation and detection limits were 15.5 and 4.6 ng ml(-1), respectively. The guidelines of the International Conference on Harmonization (ICH) were followed in order to validate the suggested procedure. The developed method was employed for the analysis of pharmaceutical preparations containing the cited drug. The obtained data were compared with those from the reported method. Good agreement was found between both methods in respect to the accuracy and precision. Moreover, the proposed method utilizes low cost reagents, and has high sensitivity. These advantages give the method the ability to be a good alternative for determination of cited drug in routine analysis.