Multilayered mucoadhesive hydrogel films based on Ocimum basilicum seed mucilage/thiolated alginate/dopamine-modified hyaluronic acid and PDA coating for sublingual administration of nystatin.

The present study establishes an experimental design for the preparation of new bi and tri-layer mucoadhesive sublingual films based on basil (Ocimum basilicum L.) seed mucilage (OBM) as novel plant-polysaccharide for oromucosal administration of nystatin (Nys). The films formulation consists of a drug reservoir-mucoadhesive layer cross-linked via CaCl2, with protective mucoadhesive layers based on thiolated alginate (TA) and polydopamine (PDA). OBM served as a new mucoadhesive polysaccharide in second layers, where the dopamine-modified-hyaluronic acid (DHA) improved the mucoadhesive strength and swelling rate properties. The drug-loaded formulations of trilayer film with PDA coating, and bilayer film with DHA/OBM (1:1) in the second layer, showed the desired mucoadhesion properties (about 69 and 75.3% respectively). The obtained results revealed that the bilayer film containing DHA had a superior swelling degree in the range of 15-19 (g/g). While the PDA coating sample showed the highest resistance to water uptake and erosion. The bilayer film (DHA/OBM with 1:1 ratio) provided a maximum drug release of 86% after 4 h. The selected formulations indicated good mechanical properties with no cytotoxicity.

Synthesis of nanohydrogels based on tragacanth gum biopolymer and investigation of swelling and drug delivery.

The present article deals with preparation of pH responsive nanohydrogels based on tragacanth gum (TG) biopolymer for drug delivery. The nanohydrogels were prepared using different chemical reagents such as 3-aminopropyltriethoxysilane (APTES) modifier and glyceroldiglycidylether (GDE), polyvinyl alcohol (PVA), and glutaraldehyde (GA) as cross-linkers. The obtained nanohydrogels were characterized using different techniques such as scanning electron microscope (SEM), elemental analysis, FT-IR, zeta sizer and thermogravimetric analysis (TGA). The gel content increased with increasing the cross-linkers contents and reached to a maximum of 90%. The swelling behavior of nanohydrogels was investigated in terms of the effect of pH (2.2, 7.4 and 9), temperature (27, 37 and 60°C), and reaction time (2-24h). Loading of Indomethacin (IND) as a model drug showed dependence on the network structure of nanohydrogels. The total in vitro IND release showed dependence on the network structure of nanohydrogels and was in the range of 50-80% at pH 9 after 24h.