Hydroxypropyl-β-Cyclodextrin for Delivery of Sinapic Acid via Inclusion Complex Prepared by Solvent Evaporation Method

The goal of this study was to increase the aqueous solubility and dissolution rate of sinapic acid (SA) by formulating binary inclusion complex (BIC) of SA with hydroxypropyl-beta-cyclodextrin (HP beta CD) using solvent evaporation (SE) technology. The phase solubility and dissolution studies were conducted to determine the solubility and in vitro release rate of SA. In addition, the prepared inclusion complex was characterized for solid state characterization using techniques such as DSC, PXRD, SEM, and FTIR. Moreover, the prepared SA-BIC was evaluated for its antioxidant activity. Results revealed that the SA solubility can be shown to improve with a change in HP beta CD concentration. About 2.59 times higher solubility of SA in water was noticed in the presence of HP beta CD (10 mM). Dissolution study demonstrated that the 34.11 +/- 4.51% of SA was released from binary physical mixture (BPM), while the maximum release of 46.27 +/- 2.79% of SA was observed for SA-BIC prepared by SE method. The prepared SA-BIC demonstrated distinctive properties when compared to pure SA, which was demonstrated by different analytical methods, such as DSC, PXRD, SEM, and FTIR, as evidence of SA inclusion into HP beta CD cavity. Further, it was observed that SA-BIC displayed stronger DPPH radical scavenging activity than SA. In conclusion, SE technology considerably enhanced the complexity of SA with HP beta CD, and these observations could help to heighten the SA solubility, which may lead to a better bioavailability.