Supramolecular polyelectrolyte complexes as mucoadhesive systems for drug delivery applications

The aim of this Thesis was the production and the characterization of a mucoadhesive device for drug delivery applications starting from a blend of two polyelectrolytes: polyacrylic acid (PAA) and branched polyethyleneimine (bPEI). Blends at two different compositions of the two polyelectrolytes (90:10 w/w PAA:bPEI and 80:20 w/w PAA:bPEI) were studied. Films and electrospun nanofibrous mats were fabricated and subjected to two different thermal treatments (100°C for 24h and 130°C for 24h) to crosslink the system. Morphological and thermal properties of the obtained devices were investigated through SEM analysis, TGA and DSC analysis, while FT-IR analysis was performed to get insight into the chemical structure of the blend system and the occurrence of crosslinking reaction. Moreover, gel content and swelling degree was evaluated. The mat with 90:10 w/w PAA:bPEI composition, thermally treated for 24 hours at 130°C was identified as the best system for drug delivery applications. In fact, a good crosslinking degree was achieved in the system (a gel content value of 96% was obtained) that allowed to maintain a good fiber morphology after immersion in water for 24h. This mat was therefore loaded with a 10% w/w of Econazole Nitrate, an antimicotic drug, and subjected to entrapping efficiency tests through HPLC, to investigate how efficiently the drug was loaded in the mat. Results showed that 93% of the initial weight of Econazole Nitrate added in the blend solution was loaded in the fibres. The characterization performed demonstrated that the produced device had suitable properties to work as a drug delivery system.