Pharmacodynamic and Pharmacokinetic Studies of β-Cyclodextrin:Dexamethasone Acetate Complexes in Mice

ABSTRACT

The aim of this study was to evaluate the in vivo activity of the anti-inflammatory and analgesic effects of a suspension of the complex composed of dexamethasone acetate (DMA) with β-cyclodextrin in comparison to a suspension of the pure DMA. Solid complexes prepared by different methods were evaluated in pharmacodynamics and pharmacokinetics studies. The pharmacodynamic effect was investigated although the capacity of the inhibited the inflammation. Models of abdominal constriction, carrageenan-induced paw oedema and formalin induced licking were used. The study of the pharmacodynamic comparison of free DMA and products of β-CDDMA demonstrated no significant difference in the majority of the tests performed. Plasma concentrations of DMA and DMAβ-CD were assayed by HPLC. A significant (p > 0.05) decrease in the relative bioavailability was obtained with the suspension containing the DMAβ-CD complex as measured by DMA plasma levels. The area under the curve (AUC) of the suspension of DMA was higher than that obtained with the suspension of the complexes. The pharmacokinetic evaluation of dexamethasone carried out on mice in the present study showed that complexed DMA with β-cyclodextrin modifieds some parameters related to the phases of absorption and elimination of this drug.