Photostability of piroxicam in the inclusion complex with 2-hydroxypropyl-β-cyclodextrin

Abstract

The aim of this work is the protection of piroxicam from photodegradation by forming inclusion complex with 2-hydroxypropyl-?-cyclodextrin. Piroxicam:2-hydroxypropyl-?-cyclodextrin molecular inclusion complex was prepared by coprecipitation method with molar ratio of 1:1. Structural characterization of the complex, the corresponding physical mixture and complexing agents of piroxicam and 2-hydroxypropyl-?-cyclodextrin was carried out by X-ray diffraction (XRD), proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FTIR). Photosensitivity to daylight for piroxicam and piroxicam:2-hydroxypropyl-?-cyclodextrin inclusion complex was investigated by Fourier-transform infrared spectroscopy. The investigations show that higher photostability of piroxicam was achieved in complex than in non-complexed piroxicam.