THERMAL STUDY OF DIFFERENT OMEPRAZOLE-GAMMA-CD CO-GROUND SYSTEMS

Techniques of DSC, TG/DTG, EGD and HSM were used to study and characte rize the complex formation and state of dispersion after co-grinding o f a 1:1 mixture of omeprazole (OME) and gamma-cyclodextrin (gamma-CD) under various conditions. The changed crystalline properties of the co mposites obtained by co-grinding suggested distinct types of interacti ons between the components, as a consequence of the variations in the grinding procedure. The experimental data clearly revealed that a true solid complex OME-gamma-CD was obtained only by wetting the mixture o f the components with phosphate buffer during the co-grinding. Other c o-grinding procedures yielded only amorphous drug-CD mixtures or their combination with partial complexation.