Gum tragacanth-polyvinyl alcohol aerogel for oral delivery of silymarin.

This study reports for the first time the fabrication of highly porous aerogels of mixed gum tragacanth-polyvinyl alcohol (GT-PVA) for loading and oral delivery of silymarin (SM). Various analytical techniques were used to investigate changes in the physical, textural, mechanical and microstructural properties of aerogels as affected by blending ratio and vacuum impregnation (VI) of SM. Results showed that the mixing ratio of 1:1 led to aerogels of larger surface area (1029.20 m·g) and superior physicochemical properties. However, at mixing ratio of 3:1 (GT:PVA) higher loading capacity (45.57% ± 2.3%) was obtained. SM loading, on the other hand, had an adverse effect on the porosity, microstructure and physical attributes of aerogels transforming them from meso-porous to macro-porous structures. The release rate of SM in simulated gastrointestinal media was found to follow Korsmeyere-Peppas model.