Interactions of naproxen with vinylpyrrolidone and beta-cyclodextrin: a fluorimetric study

A spectrofluorimetric method to study the interactions of naproxen with 1-vinyl-2-pyrrolidone and beta-cyclodextrin in aqueous solution has been proposed. As complexation causes appreciable spectral changes, this method enables the determination of the stability constants. Complexation with beta-cyclodextrin results in an enhancement of the fluorescence of naproxen whereas 1-vinyl-2-pyrrolidone involves a quenching of fluorescence. It has been supposed 1:1 complex formation. Specifically, formation constants, enthalpy and entropy values have been obtained for the aforementioned complexes at different temperatures and pH values; their associated errors are given. (C) 1997 Elsevier Science B.V.