Conception de nouveaux systèmes nano/micro encapsulés pour la vectorisation des médicaments

Abstract

The purpose of this research is to improve and optimize drug delivery systems for 5- aminosalicylic acid (5-ASA) to treat inflammatory bowel diseases such as Crohn's disease and ulcerative colitis. We used the emulsion solvent evaporation technique, which allows for the encapsulation of 5-ASA within a polymer matrix, creating microspheres that can control drug release. Our in vitro release studies in simulated gastric and intestinal fluids demonstrated controlled, pH-dependent drug release, which we successfully modeled using Higuchi’s and Korsmeyer–Peppas’ models. Additionally, we employed Design of Experiments (DOE) and Density Functional Theory (DFT) analyses to optimize molecular interactions and evaluate their effects on drug entrapment and microparticle sizes. For prolonged release in acidic medium, sodium alginate (SA) acts as a coating material, forming a stable 3D porous network with ethylcellulose (EC) and 5-ASA. This network is easily broken in basic conditions, leading to drug release. Chitosan (Cts) enhances the structural integrity of the drug-loaded beads, providing additional stability and ensuring that the drug remains effective within the gastrointestinal environment. In the optimization of colon-targeted therapy via halloysite, the biocompatibility, encapsulation capability, and pHresponsive release properties of halloysite nanotubes make them a promising material for developing targeted and controlled 5-ASA delivery systems. Diatomite serves as a promising material for drug delivery systems due to its unique properties. When combined with polymers such as sodium alginate and chitosan, diatomite can enhance the stability, biocompatibility, and controlled release of therapeutic agents. Docking experiments showed strong binding of 5-ASA to PPAR-γ and stable interactions with COX-2 enzymes, suggesting 5-ASA's potential to effectively reduce inflammation.