In the present study, we developed a moxifloxacin (MXF)-encapsulated liposome-enriched alginate nanocomposite hydrogel coating. MXF was encapsulated in soy lecithin (SL:MXF:2:1) via the probe sonication method with an average efficiency of 80%. Two different manufacturing methods, including a micropipetting and a T-shaped microfluidic junction (TMJ) device technique, were used to incorporate the MXF-encapsulated liposomes into hydrogel matrices and layered as a coating on polymeric substrate material. Drug encapsulation and its incorporation into the hydrogel matrix significantly enhanced its stability and facilitated a prolonged drug release profile. A relatively rapid drug release was observed in the MXF-encapsulated liposome-loaded polymeric particulate layer developed via the micropipetting than the TMJ device technique. The findings confirmed sustained drug release behavior due to a hydrogel particulate structural uniformity conferred by the micromachine device, TMJ. Thus, these nanocomposite hydrogel coatings achieved can serve as a promising candidate for the treatment of ophthalmic or mucosal membrane infections.

Salicylic acid is widely used in dermatological and cosmetic formulations, yet the influence of its production route on solid-state structure and biological behaviour remains underexplored. This study compares a naturally derived salicylic acid (NSA), obtained from wintergreen oil through green chemistry, with a synthetic form (SSA) produced via the Kolbe–Schmitt reaction, integrating physicochemical characterization with antioxidant and immunomodulatory profiling. Crystal morphology, crystallinity (XRD, FTIR), melting point, solubility, dissolution and Franz-cell skin permeation were determined, alongside intrinsic radical scavenging (DPPH), intracellular reactive oxygen species (DCFH-DA), cytoprotection (MTT), CD9⁺ extracellular-vesicle (EV) release and cytokine transcription in RAW 264.7 macrophages. SSA formed uniform, needle-like crystals of higher crystallinity, comparable equilibrium solubility (2.239 vs. 2.115 mg/mL; not significant) and faster dissolution, whereas the less-ordered NSA showed a numerically higher steady-state flux (39.94 ± 16.43 µg cm⁻² h⁻¹) and a shorter lag time (2.47 ± 1.71 h). SSA was the stronger radical scavenger (DPPH 20.7% vs. 8.7%) and reduced intracellular ROS more effectively, while NSA afforded greater cytoprotection. Both forms were associated with a lower CD9⁺ EV concentration in the conditioned medium following LPS stimulation, with SSA consistently more active across radical scavenging, ROS and vesicle endpoints. These findings show that the synthesis route, through its effect on solid-state properties, influences the physical performance, while the biological behaviour is discussed separately from the anti-inflammatory behaviour of salicylic acid, informing the rational selection of natural versus synthetic material for topical applications.