At present, the use of benzimidazole drugs in veterinary medicine is strongly limited by both pharmacokinetics and formulative issues. In this research, the possibility of applying an innovative semi-solid extrusion 3D printing process in a co-axial configuration was speculated, with the aim of producing a new gastro-retentive dosage form loaded with ricobendazole. To obtain the drug delivery system (DDS), the ionotropic gelation of alginate in combination with a divalent cation during the extrusion was exploited. Two feeds were optimized in accordance with the printing requirements and the drug chemical properties: the crosslinking ink, i.e., a water ethanol mixture containing CaCl₂ at two different ratios 0.05 M and 0.1 M, hydroxyethyl cellulose 2% w/v, Tween 85 0.1% v/v and Ricobendazole 5% w/v; and alginate ink, i.e., a sodium alginate solution at 6% w/v. The characterization of the dried DDS obtained from the extrusion of gels containing different amounts of calcium chloride showed a limited effect on the ink extrudability of the crosslinking agent, which on the contrary strongly influenced the final properties of the DDS, with a difference in the polymeric matrix toughness and resulting effects on floating time and drug release.

The addition of nanoparticles could allow to upgrade the performances of biopolymers, making them fit to replace petroleum-based plastics. In order to maximize the sustainability benefits of bio-nanocomposites, it is fundamental to opportunely tune their bulk properties by acting on their nanostructure. In particular, in nanocomposite blends the final morphologies are highly dependent on the selective localization of the nanoparticles: mainly inside one of the polymeric phases and/or at the interface.In this work, nanocomposite PBS (polybutylene succinate)/PLA (polylactic acid) blown films were prepared with the aim of optimizing their mechanical and gas barrier properties by profiting from the multiple functions of nanofillers as reinforcements, compatibilizers and morphology-directors. PBS/PLA blends, at a constant polymers’ weight proportion (80/20), were prepared by twin-screw extrusion, adding a constant amount of a lamellar nanosilicate (Cloisite 30B), according to different mixing routes: (i) by first dispersing the nanofillers inside the PLA or PBS phase, followed by the compounding with the other resin; (ii) by direct mixing of all the three components.The nanocomposite systems showed a finer dispersion of the PLA phase compared to the neat PBS/PLA blend. While a good exfoliation degree of the nanosilicate was generally observed for all the hybrid samples, the different blending sequence of the nanofillers significantly affected their preferential localization. In particular, the barrier and mechanical performances of the hybrid film PBS/(PLA + C30B) were most positively affected by the selective localization of the nanoplatelets at PBS/PLA interface, since their compatibilizing action was effectively exploited. In fact, this latter sample exhibited an interesting increase (+ 29%) of the deformation at break and a significant improvement (+ 33%) of the oxygen barrier compared with the neat PBS/PLA blend.

Biodegradable polymer blends are promising materials for flexible packaging films with tunable properties. In this work, poly(butylene succinate)/poly(vinyl alcohol) (PBS/PVOH) blown films were produced by twin-screw melt compounding followed by film blowing, and the effect of PVOH content on phase organization, processability, morphology, and functional performance was investigated. The blends showed phase-separated morphologies and composition-dependent structural evolution. DSC indicated that both polymers largely retained their crystallization ability, although the crystallinity decrease was more evident for PVOH. Rheological analysis revealed limited compatibility and increasing elastic response at higher PVOH contents, consistent with the formation of structured PVOH insoluble gel-like domains. SEM confirmed droplet–matrix morphologies, becoming coarser and more heterogeneous at high PVOH content, with film-blowing instability for PBS/PVOH 20/80. PVOH incorporation improved oxygen and water-vapor barrier properties and increased stiffness, but progressively reduced ductility. Model fitting supported the structure–property correlations, relating film performance to blend composition, morphology, and PVOH phase organization. Among the processable formulations, PBS/PVOH 80/20 showed the best balance between improved barrier properties and acceptable extensibility for food packaging application. Overall, PBS/PVOH blown films are promising biodegradable systems for flexible food packaging, provided that PVOH phase structuring is properly controlled.