Fluorimetric quantification of brimonidine tartrate in eye drops

A simple and sensitive spectrofluorimetric method has been developed for the estimation of brimonidine tartrate in pure and eye drops. Linearity was obeyed in the range of 0.2-3.0 ΅g/ml in dimethyl formamide as solvent at an emission wavelength (λem) of 530 nm after excitation wavelength (λex) of 389 nm with good correlation coefficient of 0.998. The limit of detection and limit of quantification for this method were 22.0 and 72.0 ng/ml, respectively. The developed method was statistically validated as per International Conference on Harmonisation guidelines. The percentage relative standard deviation values were found to be less than 2 for accuracy and precision studies. The results obtained were in good agreement with the labelled amounts of the marketed formulations. The proposed method was effectively applied to routine quality control analysis of brimonidine tartrate in their eye drops.