Pantoprazole-loaded Eudragit blended microparticles: preparation, characterization, in vitro gastro-resistance and in vivo anti-ulcer evaluation

Pantoprazole is a proton-pump inhibitor pro-drug used in the treatment of gastric ulcers and gastro-esophageal reflux disease. Pantoprazole must be absorbed intact in the gastrointestinal tract, because it is labile in the stomach environment, indicating that enteric delivery systems are required. The purpose of this study was to prepare pantoprazole-loaded microparticles by spray-drying using Eudragit S100 (M1), Eudragit RS30D (M3), or a Eudragit S100/Eudragit RS30D blend (M2). All microparticles were successfully obtained. The in vitro dissolution evaluation showed slower release from Eudragit S100 microparticles and Eudragit S100/Eudragit RS30D blended microparticles than the pure drug. The in vitro gastro-resistance assay showed that M1 and M2 microparticles were effective in protecting the drug in acid medium. After oral administration, in vivo anti-ulcer evaluation showed that the microparticles were able to protect the rat stomachs against ulcer formation by ethanol, while the drug aqueous solution did not present any activity.