Abstract

ETHYLCELLULOSE-PIROXICAM MICROPARTICLES: EFFECT OF PROCESS PARAMETERS ON ENCAPSULATION EFFICIENCY AND RELEASE PROFILE AT DIFFERENT pH

Denise Abatti Kasper Silva*, Ana Carolina Da Rosa, Larissa Delmônego, Monique De Sousa, Giovana Carolina Bazzo and Vivia Buzzi

ABSTRACT

Piroxicam(P) belongs to the nonsteroidal anti-inflammatory drugs class, may cause irritation of the gastrointestinal mucosa when administered orally, which justifies its use in the encapsulated form and Ethylcellulose (EC) is widely used as matrix. Besides that, there are effects of operating parameters on physicochemical characteristics of the particles. In this work, the effect of the conditions of production of ethylcellulose-piroxicam (EC-P) microparticles on physicochemical characteristics and the in vitro release profile under different pH were studied. The samples were obtained by emulsion solvent evaporation technic. The encapsulation efficiency (EE%) was determined by HPLC and it analyzes of some components ratio had done. The surface and morphology of microparticles recognized by SEM; drug-matrix interaction verified by TGA, DSC XRD; in vitro drug release profile were done under different pH and kinetic models applied. The EE% of piroxicam in EC matrix were in the range of 39% and 76%. The largest volume of organic phase in relation to the amount of salt in water phase and the dilution of polymer in that solvent enlarged the values of EE% of P in the EC beads. Microparticles were spherical, with absence of porous and the surface roughness. Thermal stability maintenance and reduced crystallinity of P registered. In vitro release profile showed that in low pH release 24% of P and in alkaline medium, around 33%; that is 33% higher than those recorded in an acid medium. In both medium, the release had drove by anomalous transport mechanism.

Keywords: Microencapsulation, NSAID, components ratio, sustained release, release mechanism.