Solubility Enhancement, Physicochemical Characterization and In Vivo Evaluation of the Anti-Inflammatory Activity of Sulfasalazine in Complex with β-Cyclodextrin

A complex with β-cyclodextrin was prepared to increase its solubility characteristics. The drug formulations were characterized in the solid state by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). By these physical determinations, drug–polymer interactions were found. Both the solubility and the dissolution rate of the drug in these formulations were increased. Drug contents were determined by UV spectrophotometry at a λmax of 359 nm. The phase solubility behavior of sulfasalazine in various concentrations of β-CD, in distilled water was obtained at 37 ± 2°C. The dissolution of sulfasalazine is increased with increasing amounts of the hydrophilic carriers. The complexes of sulfasalazine with β-CD were prepared at 1:1, 1:3, 1:5 and 1:7 drug/carrier ratios. The FTIR spectroscopic studies show thestability of sulfasalazine and the absence of well-defined drug–polymer interaction. The anti-inflammatory activity of sulfasalazine β-CD complex was evaluated against Carrageenan-induced rat paw oedema and Formaldehyde-induced rat hind paw edema. The Sulfasalazine β-CD (1:7) complex exhibited a higher anti-inflammatory activity than the free drug.