F. Andersen, H. Bundgaard
Apr 1, 1984
Citations
0
Influential Citations
34
Citations
Journal
International Journal of Pharmaceutics
Abstract
Abstract Metronidazole benzoate was found to form an inclusion complex with β-cyelodextrin (β-CyD) in aqueous solution and in the solid phase. A phase solubility diagram was obtained and an apparent 1:1 formation complex constant of 1.3 × 10 3 M −1 was determined. A microcrystalline inclusion complex was isolated and shown to have the stoichiometric composition of 1:1.5 (drug: β-CyD). By inclusion complexation of the metronidazole ester with β-CyD the phase transition of the clinically used anhydrous form of the compound to the monohydrate occurring in aqueous suspensions was inhibited as was the marked crystal growth resulting from the phase transition. Besides increasing the physical stability of metronidazole benzoate suspensions the complexation with β-CyD protected the drug against photochemical degradation and decreased the rate of hydrolysis.