Investigation of Curcumin-β-Cyclodextrin Complex Release in Injectable Hyaluronic Acid/Quince Seed Gum Hydrogel

Abstract Injectable hydrogels play a crucial role in various biomedical applications, serving as fillers in tissue engineering, facilitating cell repair, and contributing to the development of drug delivery systems. This study aims to investigate the release of dissolved curcumin from a new injectable hyaluronic acid/quince seed gum (HA/QSG) hydrogel. Curcumin possesses numerous biological activities, including anti-cancer, antioxidant, antimicrobial, and anti-inflammatory properties. However, due to its very low water solubility, its bioavailability is poor. To address this, curcumin was encapsulated in three inclusion complexes: Cur 1:2 β-CD, Cur 1:4 β-CD, and Cur 1:6 β-CD. These Cur-β-CD inclusion complexes were lyophilized and converted into a water-soluble form. The curcumin, bisdemethoxycurcumin, and desmethoxycurcumin content of the obtained lyophilized Cur-β-CD complexes were analyzed using the HPLC method. HA-QSG hydrogels were loaded with Cur 1:2 β-CD inclusion complex in compositions of 0.75% (w/w), 0.50% (w/w), and 0.25% (w/w). The dissolution profiles of the HA-QSG hydrogels were examined in a pH 6.8 phosphate buffer medium, used as the swelling medium in intra-articular hydrogels. The initial burst of the 0.75% (w/w) hydrogel reached 9% release within the first 15 min, whereas the 0.25% (w/w) hydrogel exhibited only 6% release during the same period. The 0.75%(w/w) and 0.50% (w/w) hydrogels displayed very similar dissolution profiles, with a slightly faster release in the early stages of dissolutions, compared to the 0.25%(w/w) Cur β-CD-HA-QSG hydrogel. The 0.25%(w/w) Cur β-CD-HA-QSG hydrogel demonstrated a relatively slower release rate particularly during the initial stage of dissolution period. However, all three formulations reached approximately 98% release within 24 h. While the 0.75%(w/w) and 0.50%(w/w) curcumin-loaded HA-QSG hydrogels, with their rapid initial release, may be suited for intra-articular applications requiring quick drug availability, the 0.25%(w/w) curcumin-loaded HA-QSG hydrogel, with its slower release, may be more beneficial for sustained intra-articular delivery. Graphical Abstract