Improving camphor solubility and stability through α-cyclodextrin encapsulation: characterization, cytotoxicity investigation, and bull sperm preservation evaluation

Abstract

Camphor, a crystalline white substance with diverse biological benefits, faces limitations in human health applications due to its volatile and hydrophobic nature, which impedes its solubility and stability. This study addresses these challenges by investigating the encapsulation of camphor within various cyclodextrins (CDs), particularly focusing on α-cyclodextrin (α-CD), to enhance its solubility and protect it from environmental degradation. The formation of camphor-CD inclusion complexes was confirmed through a combination of infrared spectroscopy (FTIR), X-ray diffraction (XRD), and ther mogravimetric analysis (TGA). Among the CDs tested, α-CD demonstrated the highest efficiency, achieving a solubility coefficient of 23.38 M⁻¹ and inclusion efficiencies of 24.37% and 34.63% for 1:1 and 1:2 stoichiometries, respectively. Biological evaluations revealed that the Camphor/α-CD complex exhibited significant preservative effects on sperm motil ity at low concentrations while demonstrating a toxic effect on red blood cells. Additionally, the complex showed promis ing radical scavenging activity as assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. These findings suggest that camphor, when complexed with α-CD, holds considerable potential for novel applications in drug delivery and cryopreservation technologies.