Lignin-Hydroxypropyl-β-Cyclodextrin Matrix for Chlorzoxazone Loading and Release: Physicochemical, Antioxidant, and...

Chlorzoxazone (CLZ) is a poorly water-soluble drug whose formulation may benefit from carrier systems capable of drug incorporation and controlled release. This study investigated an epichlorohydrin (ECH)-mediated lignin-hydroxypropyl-β-cyclodextrin (LIG/HP-β-CD) matrix for CLZ loading and release and evaluated its physicochemical, antioxidant, and antimicrobial characteristics. The resulting material was characterized by Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TG/DTG), while CLZ release was evaluated using kinetic models. The experimentally determined CLZ loading was 41.8 mg/g, corresponding to a loading efficiency of 20.9% relative to the initially added drug. After 180 min, the cumulative amount released reached 29.81 mg/g, corresponding to 71.32% of the loaded CLZ. The release profile was adequately described by the Weibull model (R² = 0.99394), which provided a useful empirical description of the observed release behavior. FTIR analysis showed changes in the relative contributions of oxygen-containing functional-group regions after modification, while TG/DTG demonstrated an altered thermal profile of the CLZ-loaded material compared with the individual components; these findings were interpreted as supportive rather than definitive evidence of drug-matrix interactions. DPPH radical-scavenging activity was 41.82 ± 1.07% for LIG and 50.32 ± 1.05% for LCD-CLZ; however, because the samples were tested at different concentrations, these values were not interpreted as demonstrating an intrinsic enhancement of antioxidant potency. Under the agar-diffusion conditions, LCD-CLZ produced measurable inhibition against Staphylococcus aureus, Escherichia coli, and Candida albicans, whereas no effective inhibition was observed against Pseudomonas aeruginosa. Overall, the results support further investigation of the LIG/HP-β-CD matrix as a potential platform for CLZ loading and release, while additional structural, biocompatibility, and formulation-specific studies are required before pharmaceutical application can be established.