Design and In Vitro Optimization of the Gastroretentive Microparticles Using Ethylcellulose and Eudragit

Abstract

The biocompatible and bioadhesive polymers ethylcellulose and eudragit S100 are often used for controlled delivery of drugs in low pH conditions. Recent research focuses on designing and optimizing multiparticulate floating and bioadhesive systems using a central composite approach. Gastro-retentive floating microparticles of ethylcellulose and eudragit S100 containing itopride hydrochloride (ITH) were prepared using a solvent evaporation method. The impact of several process variables, including drug-polymer ratio, were studied on physicochemical parameters such as drug entrapment efficiency, particle size, bioadhesion, and release by employing a central composite design strategy. The experimental results were in good agreement with the predicted values of the optimization technique. The optimized microparticles had a 94.77 % drug entrapment efficiency, a particle size of 259.2 µm, 96.98 % drug release in simulated stomach fluid (pH 1.2) after 12 hours, and an 8-hour floating lag time. An accelerated stability analysis was conducted on the optimized formulation according to ICH criteria, and no significant changes in drug quantity were identified during storage. The microparticulate formulation containing ethylcellulose to eudragit S100 (in the ratio of 9:3) prepared by solvent evaporation technique displayed suitable pharmaceutical characteristics for controlled gastro retentive delivery of ITH. Furthermore, the results of the stability studies indicated that the developed formulation had not undergone any major changes under stress.