Marijana M. Dragosavac

Thyme oil (TO) is emerging as a promising candidate to counteract antimicrobial resistance due to its renowned antimicrobial and anti-inflammatory properties. However, rapid gastric absorption of its bioactive compounds limits its intestinal delivery, where its action is required, so the protection of these components is necessary. This pilot study optimized TO-loaded emulsions for targeted intestinal release. High-shear homogenization and membrane emulsification were compared to formulate single oil in water (O/W) and double water in oil in water (W/O/W) emulsions, screening emulsifiers (lecithin, Tween 20, Tween 80) and functional biopolymers (pectin, sodium alginate). High-shear homogenization with lecithin (0.5%), pectin (1.80%), and sodium alginate (0.2%) yielded stable submicron O/W emulsion (Span = 0.5; d(v,0.5) = 0.21 µm), achieving electrostatic stabilization (ζ-potential = −51.5 ± 1.5 mV) at a target poultry dosage. A pH-responsive behavior was observed: protective hydrogel formed in gastric conditions (d(v,0.5) = 2.64 µm) and maintained stability at intestinal pH (d(v,0.5) = 3.03 µm). Membrane emulsification enabled precise droplet control under mild conditions, producing monodisperse O/W emulsions (d(v,0.5) = 38–59 µm; Span ≤ 1.0) and W/O/W double emulsions (d(v,0.5) = 26.5 µm; Span = 0.6) with ultra-low interfacial tension (0.52 mN·m⁻¹). Repeated membrane passes reduced droplet size to ~6.6 µm. These systems represent a foundational step toward bioactive intestinal delivery, providing a viable antibiotic-free strategy for sustainable livestock production.

In this study, two novel spherical agglomeration processes based on membrane systems were successfully implemented to produce spherical agglomerates of benzoic acid crystals obtained via antisolvent crystallization. Two membrane configurations were considered: a flat disc mounted in a dispersion cell equipped with a mixing impeller, and a second configuration which uses a cylindrical membrane equipped with a vibrating module which created shear with upward–downward vibration. To optimize the performance of the spherical agglomeration process, the impact of the bridging liquid flowrate, membrane pore size and pore arrangement, as well as agitation rate were investigated. Both systems were successfully used to generate spherical agglomerates with enhanced quality and size distribution at comparable flux conditions. This work opened new opportunities to investigate the scalability of the proposed spherical agglomeration system under the optimized operating conditions identified from the current study.

Membrane emulsification has the potential to revolutionize the energy‐efficient production of uniform emulsions and dispersions, relevant to diverse fields from pharmaceutical active ingredient controlled release particles to Fast Moving Consumer Goods. A novel highly robust single‐pass continuous phase crossflow system has been developed providing dispersed phase concentrations up to 40% vol/vol and dispersed phase fluxes up to 5,730 L m⁻² hr⁻¹, from a single 100 mm long membrane tube. Extensive results of two oil‐in‐water systems (vegetable oil and PolyCaproLactone dissolved in DiChloroMethane) and one water‐in‐oil system (sodium silicate solution) are reported, using hydrophilic and hydrophobic membranes respectively. Mathematical models are validated enabling comprehensive engineering analysis of processes including predicted droplet size, membrane pressure drops, and energy requirement for dispersion production. Surfactant depletion, pore utilization, and droplet interaction at the membrane surface were investigated to provide a comprehensive analysis of the capabilities of novel annular‐flow membrane emulsification for high throughput emulsion generation.