Preparation and physicochemical characterization of omeprazole:methyl-beta-cyclodextrin inclusion complex in solid state

Abstract In this work, we illustrate the usefulness of cyclodextrins, namely, methyl-ß-cyclodextrin (MßCD), an amorphous, methylated derivative of the natural ß-cyclodextrin (ßCD), as a tool to form an inclusion complex with omeprazole (OME), a poorly water soluble drug. Solid binary systems between OME and MßCD were prepared experimentally in a stoichiometry 1:1 by different techniques (physical mixing, kneading, spray-drying and freeze-drying). Afterward these products were characterized by Fourier transformation-infrared spectroscopy (FTIR); X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results obtained suggest that spray-drying and freeze-drying methods yield a higher degree of amorphous entities suggesting the formation of inclusion complexes between OME and MßCD

Evaluation of host-guest complex formation between a benzimidazolic derivative and cyclodextrins by UV-VIS spectrophotometry and differential scanning calorimetry

Abstract Interactions between a benzimidazolic derivative, omeprazole (OME), beta-cyclodextrin (ßCD) and a chemically modified ßCD, methyl-beta-cyclodextrin (MßCD) were investigated in aqueous solution by UV-VIS spectroscopy and in solid state by differential scanning calorimetry (DSC). Phase solubility studies were used to evaluate the complexation in aqueous solution. The two solubility diagrams obtained were AL type, indicating the formation of a drug-cyclodextrin complex with 1:1 stoichiometry. The complex of OME with MßCD showed a higher stability constant (K S) than those with ßCD. Some evidences of inclusion complexation in solid state were obtained from DSC. Only in thermal curves of OME-ßCD lyophilized product and in OME-MßCD spray-dried and lyophilized systems the melting point of the drug disappeared completely suggesting the possible formation of an inclusion complex