Optimization of pH-responsive carboxymethylated iota -carrageenan/chitosan nanoparticles for oral insulin delivery using response surface methodology

In designing an oral delivery method for insulin, we previously reported that pH-responsive carboxymethylated kappa-carrageenan-based microparticles protected insulin from acid degradation during transport through the gastrointestinal tract. However, the low surface-to-volume ratio of these microparticles and the presence of only one sulfate group in each kappa-carrageenan subunit for insulin stabilization may lead to a suboptimal delivery...