Fluorescence piroxicam study in the presence of cyclodextrins by using thePARAFAC method

The nonsteroidal anti-inflammatory drug Piroxicam is of interest not only i n pharmacology and therapeutics but also in structural dynamics. This drug in solution presents several equilibria that depend on its conformational s tructure and the medium. Piroxicam was studied by total fluorescence by usi ng a chemometric method (parallel factor analysis or PARAFAC) to resolve it s spectra. The addition of cyclodextrins can promote the encapsulation of s ome preferred Piroxicam species and more easily affect the spectral deconvo lution. Because each species has a distinct spectrum as a function of the d egree of encapsulation, a factorial fractional design (face-centered fracti onal cubic with a central sample) was considered for different cyclodextrin s solutions. It was possible to identify a correlation between some spectra and the isomers and to reach some understanding of the spectroscopic behav ior of the drug in cyclodextrin-containing hydrophilic solvents.