The Study of Fluorescence Quenching Norfloxacin by Ascorbic Acid

Abstract

Currently, drug/drug or food/drug interactions are great field of study, due to rapid development of new types of drugs and increasing use of food supplements. The interactions of ascorbic acid (AA) with norfloxacin (NRF) were investigated by fluorescence quenching, UV/vis and Fourier transform infrared (FTIR) spectroscopic techniques. The results of the study indicated that the fluorescence quenching between ascorbic acid and norfloxacin could be rationalized in terms of static quenching or the formation of non-fluorescent AA-NRF complexes. From fluorescence quenching spectral analysis the binding constant , number of binding sites (n), and thermodynamic properties, were determined. The quenching constants is 2.27 × 10 3−1 at 298K and binding sites n is 2. The thermodynamic parameters determined by using Van’t Hoff equation. The determined thermodynamic parameters suggest that the binding process occurs spontaneously by involving hydrogen bond and van der Waals forces played the major role in the reaction of AA with NRF.