Drug loading into β-cyclodextrin granules using a supercritical fluid process for improved drug dissolution

To improve dissolution properties of drugs, a supercritical fluid (SCF) technique was used to load these drugs into a solid carrier. In this study, granules based on β-cyclodextrin (βCD) were applied as a carrier for poor water-soluble drug and loaded with a model drug (ibuprofen) using two different procedures: controlled particle deposition (CPD), SCF process and solution immersion (SI) as a conventional method for comparison.Using the CPD technique, 17.42 ± 2.06 wt.% (n = 3) ibuprofen was loaded into βCD-granules, in contrast to only 3.8 ± 0.15 wt.% (n = 3) in the SI-product. The drug loading was confirmed as well by reduction of the BET surface area for the CPD-product (1.134 ± 0.07 m2/g) compared to the unloaded-granules (1.533 ± 0.031 m2/g). Such a reduction was not seen in the SI-product (1.407 ± 0.048 m2/g). The appearance of an endothermic melting peak at 77 °C and X-ray patterns representing ibuprofen in drug-loaded granules can be attributed to the amount of ibuprofen loaded in its crystalline form. A significant increase in drug dissolution was achieved by either drug-loading procedures compared to the unprocessed ibuprofen.In this study, the CPD technique, a supercritical fluid process avoiding the use of toxic or organic solvents was successfully applied to load drug into solid carriers, thereby improving the water-solubility of the drug.