[Evaluation of beta-cyclodextrins as formulated coadjuvants for improved drug solubility]

Cyclodextrins are known to form inclusion complexes in acqueous solutions with various types of organic substance, also a lot of hydrophobic drugs. Drugs/beta CD complexes obtained applying different techniques, eventually in solid state, usually show an improvement of solubility or at last in dissolution characteristics. In the present work, drug-bCD system or interacted products are prepared in order to screen different method of preparation in respect to the bioavailability increase (evaluated in vitro) and to the feasibility of the manufacturing process. From the galenical development point of view the beta CD/drug system prepared in different molar ratios were characterized by their physico-chemical properties (melting point, thermal behaviour by DSC, moisture content, IR spectrum, UV spectrum, equilibrium solubility, dissolution kinetics). The applied methods of preparation are well known industrial process as dry mixing (simple physical mixture), co-milling, kneading, coprecipitation, freeze drying, wet granulation methods. From the obtained in vitro results, it would seem that solubility and dissolution characteristics are improved by the drug-beta CD interaction, applying very common simply economic methods so the choice of the preferred manufacturing method will be delayed depending on in vivo performance and clinical needs and long term stability studies.