Comparison the solubility and dissolution rate effects of beta-cyclodextrin and gamma-cyclodextrin complexations of rosuvastatin calcium

The present work focuses on the inclusion complexations (ICs) of rosuvastatin calcium (RSV) with beta (b) ve gama (g) derivatives of native cyclodextrins (CDs) and investigate effects on improved solubility and dissolution rate. The phase solubility studies illustrated that RSV solubility increased in the presence of gCD with a negative deviation that indicates AN type diagrams, while βCD showed Bs type, upon addition of βCD, an increase in the solubility of the drug was observed up to a particular point. ICs of RSV were prepared with β and gCD by at 1:1, 1:2 and 1:4 different molar ratios by freeze drying method. FT-IR and DSC results revealed formation of ICs between RSV and CD. High drug loading efficiency was obtained for all ICs in the range of 99.41–101.84%. Water solubility studies showed that βCD ICs have increased solubility of RSV about 1.3 times regardless of CD ratios(p>0.05). As compared to βCD ICs, RSV solubility was significantly greater in gCD ICs and increased up to 1.45, 1.72 and 2.00 fold at 1:1, 1:2 and 1:4 ratio, respectively. Conspicuously, RSV solubility increased with increasing ratio of gCD(p<0.05). Compared dissolution profiles with pure RSV, all ICs showed improved dissolution rates and immediate release profiles. However multiple point comparison of dissolution profiles indicated that gCD ICs have higher drug release. Particularly gCD ICs at 1:4 ratio released the highest RSV with 95.12% at 3 min and 100% completion in 15 min. It is concluded that gCD provided a better improvement on RSV solubility and dissolution rate than βCD.