Drug delivery from mucoadhesive disks based on a photo-cross-linkable polyaspartamide derivative

Disks for local delivery of amoxicillin to the buccal or gastric cavity were prepared using as starting polymer a polyaspartamide derivative. In particular, alpha,beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) was derivatized with glycidyl methacylate (GMA) in order to synthesize PHG, a photo-cross-linkable and biodegradable polymer that gives rise to the formation of a chemical hydrogel (PHG-UV) by irradiation. This hydrogel was shaped as disks whose mucoadhesive properties have been confirmed by swelling measurements in phosphate buffer/citric acid solution at pH 7.0 in the presence of various concentrations of mucin. Swelling ability of PHG-UV disks was also evaluated in simulated salivary and gastric fluids. Antoxicillin was soaked into PHG-UV disks and its release was evaluated in simulated buccal and gastric conditions. The results obtained showed that the prepared disks also provide a reduction of the drug degradation in acidic medium.