Self-emulsifying drug delivery systems with atorvastatin adsorbed on solid carriers: formulation and in vitro drug release studies

Abstract

Two novel self-emulsifying drug delivery systems (SEDDS) with atorvastatin calcium, an anti-hyperlipidemic drug, were obtained and adsorbed on different solid inorganic carriers. In order to determine the parameters affecting the drug release process, different physicochemical analyses were performed. Liquid SEDDS were investigated for water solubilization capacity, viscosity and surface tension. In the case of solid materials, differential scanning calorimetry and scanning electron microscopy were conducted in order to check the samples for the presence of drug crystals. The interactions between the components of the materials were analyzed with inverse gas chromatography and Flory-Huggins parameters were calculated. The drug release experiments performed for all investigated formulations revealed that after the initial quick release the drug concentration in the dissolution medium decreased slightly which might be related to the crystallization process. However, the level of the released active ingredient was maintained at 80% for most formulations. It was also shown that the results of drug dissolution studies were independent of the measured physicochemical parameters, even though some clear differences have been observed between the analyzed materials.