Mathematical Modeling of Water-Soluble Astaxanthin Release from Binary Polysaccharide/Gelatin Blend Matrices

Water-soluble AstaSana astaxanthin (AST) was loaded into 75/25 blend films made of polysaccharides (carboxymethyl cellulose (CMC), gum Arabic (GAR), starch sodium octenyl succinate (OSA), water-soluble soy polysaccharides (WSSP)) and gelatin (GEL) at levels of 0.25, 0.5, and 1%, respectively. Due to the presence of starch granules in the AST formulation, the supplemented films exhibited increased surface roughness as compared to the AST-free films. Apart from the CMC/GEL carrier, the migration of AST to water (25 °C, 32 h) was incomplete. Excluding the CMC-based carrier, the gradual rise in the AST concentration decreased the release rate. The Hopfenberg with time lag model provided the best fit for all release series data. Based on the quarter-release times (t_25%), the 0.25% AST-supplemented OSA/GEL film (t_25% = 13.34 h) ensured a 1.9, 2.2, and 148.2 slower release compared to the GAR-, WSSP- and CMC-based carriers, respectively. According to the Korsmeyer–Peppas model, the CMC-based films offered a quasi-Fickian release of AST (n < 0.5) with the burst effect (t_100% = 0.5–1 h). In general, the release of AST from the other films was multi-mechanistic (n > 0.5), i.e., controlled at least by Fickian diffusion and the polymer relaxation (erosion) mechanism. The 1% AST-added WSSP/GEL system provided the most linear release profile.