Study of the Inclusion Complexation of Piroxicam - \beta - Cyclodextrin and Determination of the Stability Constant (K) by UV-Visible Spectroscopy

Over the past four decades, interest in the physical and chemical properties of inclusion complexes has grown considerably. One of the most important reasons for this is the relevance that inclusion complexes have to enzyme substrate and drug-receptor interactions. Inclusion complexation between the drug piroxicam and $\beta$-cyclodextrin was investigated by using the simple and easily accessible UV-visible spectroscopy technique, and the stability constants of the inclusion complexes at two different concentrations of the guest molecule were calculated. The stability constant of the inclusion complex with a diluted solution of the piroxicam drug was \overline{K}=24.75\pm5.89 mol^{-1}.L at \lambda_{max}=352 nm and that of the saturated solution of piroxicam was calculated to be: K=69.35\pm5.65 mol^{-1}.L at \lambda_{max}=285 nm and K=56.34\pm8.34 mol^{-1}.L at \lambda_{max}=251 nm.