Fabricating the polysaccharides-based Micro-particles co-encapsulating the hydrophilic-hydrophobic vitamins (B9 and D3) using spray-dried pickering double emulsions: Assessment of multilayered microcapsules structure, retention stability, encapsulation efficiency, and in vitro release

Vitamin B₉ and D₃ deficiencies are becoming the primary concern worldwide due to poor bioavailability. Both vitamins exhibit sensitivity towards storage and processing conditions, which limit their use to develop functional products. This study developed co-encapsulation of Vit. B₉ and D₃ solid microcapsules using W₁-O-W₂ multiple Pickering emulsions, followed by spray drying. The study examined the effects of four polysaccharide-based gels (PBGs) calcium alginate, carboxymethylcellulose, hydroxypropyl methylcellulose, and guar gum—used as co-encapsulants for microcapsules. Key parameters analyzed included structural characteristics, encapsulation efficiency (EE), retention stability, and gastrointestinal simulation release of the microparticles. The electrical bonding of Vit. B₉ with chitosan in W₁ and multilayering capsule in emulsion caused the high encapsulation efficiency (92.4 ± 0.6 %) and Vit. D₃ 82.4 ± 0.1 %). Furthermore, adding PBGs into the outer aqueous phase improved the particle integrity (size 10–100 µm) and enhanced the retention efficiency (60.2 ± 1.5–73.4 ± 1.2 % (B₉), 76.4 ± 2.5–88.1 ± 1.5 % (D₃)) and EE of vitamins. Structural analysis, i.e., optical microscopy, XRD, and FTIR of dried microcapsules, demonstrated the successful entrapment of vitamins and in vitro control release of Vit. B₉ and D₃ mechanisms are conferring the protectiveness of W₁-O-W₂ against the gastrointestinal environment. The formulation comprising carboxymethylcellulose displayed a controlled release of vitamins under simulated gastric conditions (SS, SGJ) and the highest cumulative release (40.8 ± 1.3 % D₃ and 51.1 ± 1.6 % B₉) under simulated intestinal conditions (SIJ), with higher stability (55.8 ± 1.7 %Vit D₃ and 69.8 ± 2.0 % Vit B₉) at 25 °C up to 8 weeks. This study demonstrates that employing W₁-O-W₂ in conjunction with a spray drying technique for co-encapsulating lipophilic and hydrophilic components using PBGs as co-encapsulants may improve the physicochemical stability and bioavailability of the encapsulated entities.