The aim of this study was to modify the release and thus enhance the bioavailability of a calcium antagonist cinnarizine whose aqueouse solubility is low and half-life is short. For this purpose, solid dispersion system was chosen as the delivery system since it is a simple method at laboratory conditions and it is belived to increase the dissolution of the active agents. Eight formulations of solid dispersions were prepared using four different methods and two different vehicles, to investigate the effects of the preparation method and the vehicle used on the release of the active ingredient, cinnarizine. For the characterization of cinnarizine solid dispersions, cinnarizine amount, practical yield %, thermal, particle size distribution and X-ray diffraction analysis were performed. In vitro dissolution from hard cellulose capsules containing cinnarizine solid dispersions was compared to pure cinnarizine. Aqueous dispersions of pure cinnarizine and the formulation selected depending on the results of the in vitro analyses were applied to rabbits orally. As a conclusion of the in vitro-in vivo evaluations of solid dispersions planned to be developed for increasing cinnarizine absorption potential, it was determined that the dissolution could be modified and the bioavailability could be enhanced.