Mucoadhesive hybrid polymer/liposome pastes based on modified polysaccharides

Abstract Mucoadhesive hybrid polymer/liposome paste is a new drug delivery system presenting controllable and tailorable delivery mechanism. By using mucoadhesive material the delivery can be more specific and local. Here we present a study investigating the effect of polymer type, concentration, functional end group and crosslinking on the release profile of nano liposomes from polymer pastes. Polymer pastes can be expected to combine the mucoadhesion mechanisms of dry and wet dosage forms but have not been studied extensively. In order to better understand the mucoadhesion of pastes, we investigated a series of pastes based on the same polymer and used different chemical modifications that can produce interactions at different levels. Native and thiolated polymers presented enhanced mucoadhesion in a wet environment in comparison to acrylated polymers which dissolved rapidly due to the enhanced solubility of PEG chains in water. Paste crosslinking resulted in a sustained release profile compared to non-crosslinked pastes. Pectin-SH pastes, especially 3% (w/v), showed a linear liposomal release profile which is ascribed to the combination of ionic crosslinking and di-sulfide bridging. By configuring the polymer type or concentration we can control the release mechanisms and achieve distinct inherent properties which can be applied for diverse medical applications.