Enhancement of dissolution of Atorvastatin through preparation of solid dispersions using supercritical fluid technology
Rana M Obaidat, Walaa Malkawi and Bashar Altaani
Jordan University of Science and Technology, Jordan
: J Pharm Drug Deliv Res
Supercritical fluid technology (SFT) method offered many advantages in the pharmaceutical area for heat sensitive materials, drying process and preparation of carriers and recently for solid dispersions. The aim of this study was to enhance the dissolution of Atorvastatin as class II model drug. SFT was employed in sample preparation. Selected polymers were polyvinylpyrrolidone (PVP K30), polyethylene glycol (PEG 6000), SoluplusÂ®, and chitosan. Full physicochemical characterizations including in-vitro release were performed. The drug was mixed physically with one of the polymers (PVP K30, PEG 6000, Soluplus or chitosan carrier) to produce mixture of drug to polymer in ratio of 1:9. Then, it was processed by SFT apparatus. The overall loading efficiency for all prepared SDs was very good with values higher than 59%. Enhancement of rate of dissolution was achieved in the prepared dispersions. The drug was precipitated as crystalline form in all prepared dispersion. Drug peaks appeared in FTIR for all PMs and SDs indicating absence of chemical interaction between the drug and the polymers though weakening of N-H stretching bond indicated possibility of interaction between Atorvastatin with SoluplusÂ®. SEM analysis for PVPK30, and PEG 6000 dispersions suggested deposition of the drug particles on the surface of the polymer. On the other hand, SD prepared using SoluplusÂ® shows that the surface of the polymer has been foamed and bubbles have been formed. While the particles of the drug were observed clearly in porous structure of chitosan carrier with powder X-ray diffraction indicating the crystalline nature of the drug. All prepared dispersions showed chemical stability except for PVP dispersions which formed stick paste. In conclusions, enhancement of dissolution was achieved through preparation of solid dispersions using SFT solvent free method.