Cyclodextrin inclusion complex of a multi-component natural product by hot-melt extrusion

This study aimed to investigate whether hot-melt extrusion (HME) processing can promote molecular encapsulation of a multi-component natural product composed of volatile and pungent hydrophobic substances (ginger oleoresin (OR)) with cyclodextrins. 6-Gingerol and 6-shogaol, the biomarkers of ginger OR, were quantified by HPLC. Phase-solubility studies were performed using beta-cyclodextrin (beta CD) and hydroxypropyl-beta-cyclodextrin (HP beta CD) for ginger OR complexation. Solid complexes were then prepared by thermal (HME)- and solvent (slurry (SL))-based methods. Morphology, thermal behavior, solubility, in vitro dissolution, and in vivo anti-inflammatory activity were evaluated. HP beta CD gave rise to AL-type complexes with ginger OR, whereas beta CD led to materials with limited solubility. Ginger OR was complexed with HP beta CD by HME without significant change in gingerol and shogaol content. Additionally, thermogravimetric analysis (TGA) suggested higher volatile retention in HME complexes than in SL ones. Shogaol and gingerol solubility and dissolution significantly increased from SL and HME complexes compared with ginger OR. In turn, 1:2 OR/HP beta CD HME complex showed higher 6-shogaol solubility than SL, associated with a gradual release. The carrageenan-induced pleurisy test showed that the anti-inflammatory activity of ginger OR was maintained after complexation with HP beta CD. The complexes significantly decrease the levels of IL-1 beta and inhibit cell migration. HME complex showed performance equivalent to the positive control and superior to the SL material. Taken together, these results indicate that HME can be useful for promoting the molecular encapsulation of complex natural products that contain volatile and thermolabile substances. HME complexes showed better in vivo and in vitro performance than complexes prepared using the solvent-based method.

Automated summary

This study investigated the use of hot-melt extrusion (HME) processing for molecular encapsulation of a multi-component natural product, ginger oleoresin (OR), with cyclodextrins. The results showed that HME complexes exhibited better solubility, dissolution, and anti-inflammatory activity compared to solvent-based complexes. These findings suggest that HME can be a useful method for encapsulating complex natural products containing volatile and thermolabile substances.