Physico-chemical and mechanical properties and controlled release in coated pellets of mixing films between ethylcellulose and ammonio methacrylate copolymer in organic and aqueous dispersion systems

Abstract

The properties of single film and mixed film of ethylcellulose and ammonio methacrylate copolymer type B prepared in organic system (ethylcellulose and EudragitⓇRS100) and aqueous dispersion system (Surelease and EudragitⓇ RS30D) were investigated. The effect of type and amount of plasticizers on their physico-chemical and mechanical properties of film as well as on the release of the drug from propranolol hydrochloride pellets coated with these single film and blended films were observed. The propranolol hydrochloride pellets were prepared by extrusion-spheronization technique and were coated by a Wurster type fluidized bed technique. The surface appearances and the mechanical properties of single polymer and polymer blends were affected by the various types and amounts of plasticizers. For the organic system, dibutyl phthalate could improve appearances and mechanical properties of ethylcellulose and the polymer blends with higher portion of ethylcellulose while triethyl citrate could improve appearances and mechanical properties of BudgetⓇ Rs100 and the polymer blends with higher portion of Eudragit Ⓡ RS100. All of the triethyl citrate-plasticized films prepared from aqueous dispersion system produced soft and tough films with smooth surface. An increase in amount of plasticize could produce good properties of both surface appearances and mechanical properties. The different type and amount of plasticizers could also modify the drug release characteristics. The incorporation of EudragitⓇRS100 in the blended films improved the smoothness of the coating surface but the incorporation of EudragitⓇ RS5OD did not improve the surface appearances of the blended films. Nevertheless, the mixtures of two polymers in both systems could retard drug release characteristics when compared to the pure film of EudragitⓇRS type. The interaction between two polymers prepared from aqueous dispersion system was revealed by the IR spectra whereas the X-ray diffractograms could not detect any interaction of two polymers in aqueous dispersion system.