Enhanced Solubility and Dissolution Rate of Raloxifene using Cycloencapsulation Technique

The aim of this study was to improve the water solubility of raloxifene by complexing it with sulphobutylether-β-cyclodextrin. Inclusion complexation in aqueous solution and solid state was evaluated by the phase solubility diagram, powder X-ray diffractometer, Fourier-transform infrared spectroscopy, nuclear magnetic resonance, scanning electron microscopy, hot stage microscopy and transmission electron microscopy. The inclusion complex behavior of raloxifene and sulphobutylether-β-cyclodextrin were examined by molecular modeling method. The phase solubility diagram with sulphobutylether-β-cyclodextrin was classified as AL-type curve, indicating the formation of 1:1 stochiomatric inclusion complex. The apparent solubility constants calculated from phase solubility diagram was 753 M-1. Aqueous solubility and dissolution studies indicated that the dissolution rates were remarkably increased in inclusion complex, compared with the physical mixture and drug alone. In conclusion, inclusion complexation with sulphobutylether-β-cyclodextrin is an easy approach to increase raloxifene solubility and dissolution rate which could have implications in its bioavailability considering it a Biopharmaceutical Classification System Class II drug.