Design, statistical optimization, in vitro and biological characterization of Eudragit L100-gelatin based...

This study deals with the development of a bilayer biodegradable mucoadhesive patch using the solvent casting approach, incorporating a ropivacaine (RC)-loaded gelatin layer and an itopride (IP)-loaded eudragit L100 layer for managing oral mucositis, nausea, vomiting, and gastrointestinal disorders. The patch was evaluated for several parameters including patch thickness, weight variation, folding endurance, moisture content, surface pH, drug content, in-vitro drug release, stability, swelling ratio, and water absorption capacity. The layers were optimized using a Box-Behnken Design, while studying the effect of concentration of gelatin or eudragit, plasticizer, drying temperature and drying time on dependent variables such as film weight, film thickness, swelling capacity, and disintegration time. The RC-gelatin layer exhibited weights ranging from 200 to 2120 mg, swelling of 35-85 %, and disintegration times between 8 and 22 h, with a drug content of 94-102 %. The eudragit layer demonstrated controlled drug release (60 % over 8 h). FTIR, TGA, DSC and XRD confirmed compatibility of ingredients, while SEM demonstrated homogeneous drug distribution. Negative zeta potential (-16.8 mV) confirmed the stability of patch. Tail flick tests in rats confirmed local anesthetic action, and strong mucoadhesive strength was observed in rabbits' buccal mucosa. Cytotoxicity studies exhibited enhanced cell survival, while histopathological analysis demonstrated no inflammatory or harmful effects, confirming the safety of the patch.