Rapid and sensitive spectrofluorimetric method for the estimation of celecoxib and flurbiprofen

In this study new, rapid and sensitive spectrofluorimetric methods for the quantitative estimation of celecoxib and flurbiprofen in pure form and in their pharmaceutical dosage forms were developed. The solvent systems, wavelengths of detection (excitation and emission) were optimized in order to maximize the sensitivity and minimize the cost of analysis for both the drugs. No extraction procedure was employed for analysis of these compounds in their formulation matrix, which reduced the time of sample preparation. The excitation and emission wavelengths were found to be 256 nm and 403 nm respectively for celecoxib in water and 250 nm and 314 nm respectively for flurbiprofen in 1:1 mixture of methanol and 0.1N sulphuric acid. The linear regression equations obtained by least square regression method for fluorescence intensity (FI) and concentration in ng/ml (conc) were FI=1.2874´conc+22.647, for celecoxib; and FI=27.7970´conc+46.049, for flurbiprofen. The limit of detection as per the error propagation theory was found to be 4.97 ng/ml and 0.99 ng/ml for celecoxib and flurbiprofen respectively. The developed methods were successfully employed with high degree of precision and accuracy for the estimation of total drug content in two commercial capsule formulations of celecoxib and two ophthalmic drops of flurbiprofen. The results of analysis were treated statistically, as per International Conference on Harmonization guidelines for validation of analytical procedures, and by recovery studies. It was concluded that developed methods are simple, accurate, sensitive, precise and reproducible and could be applied directly and easily to the pharmaceutical preparations of celecoxib and flurbiprofen.