Gemfibrozil is a lipid-regulating active substance. Dimethyl-b-cyclodextrin products were prepared from this sparingly soluble pharmacon by means of methods such as physical mixing, kneading, spray drying and ultrasonication. After the complex examination process, solid dosage forms (tablet, capsule) were prepared from the selected products on the basis of their dissolution profile and the in vitro membrane diffusion results. This publication details the investigation results of these products, and the preparation and examination of the solid dosage forms. The interactions leading to complex formation between the components of the products were examined by DSC, FTIR, X-ray, and 1H-NMR methods.