Encapsulation of 5,7-Dimethoxyelavone/ hydroxypropylcyclodextrin inclusion complexes in chitasan particles

Abstract

5,7-Dimethoxyflavone (5,7-DMF) is a flavonoid reported to have many pharmacological properties. However, the pharmaceutical uses of this compound were limited due to its low water solubility. In this research, the water solubility of 5,7-DMF was improved by inclusion complex with 2-hydroxypropyl-β-cyclodextrin (HPβCD) using a lyophilizing method. Phase solubility showed stability constant of 1840 M⁻¹ while Job’s method affirmed 1:1 stoichiometry. Furthermore, FTIR, DSC, XRD, 1D, and 2D NMR were performed to prove the formation of inclusion complex. Moreover, the 5,7-DMF/HPβCD inclusion complexes were further loaded in chitosan nanoparticles. The loaded chitosan nanoparticles were prepared using ionotropic gelation and ultrasonication method. The ultrasonication could be used for decreasing the particle size and increasing the entrapment efficiency. Treated ultrasonication for 5 minute, chitosan nanoparticles containing 5,7-DMF/HPβCD inclusion complex (IC-uCSNP) with the ratio of chitosan/inclusion complex/TPP as 4/2/1 w/w/w have a high entrapment efficiency (> 60%) with average size of 203 ± 3 nm. Controlled release studies performed in vitro at pH 1.2 and pH 7.4 showed an initial burst effect and followed by a slow 5,7-DMF/HPβCD inclusion complex release (74% and 62.8% within 24 h, respectively).