FLUID PROPERTIES OF COMPONENTS FOR DEVELOPMENT OF EUDRAGIT RS-BASED IN SITU-FORMING GEL AND MICROPARTICLE AND THEIR PHASE INVERSIONS

Solvent exchange-induced in situ-forming gel (isg) and in situ-forming microparticles (ism) have been currently applied as drug delivery approaches for periodontitis treatment. Doxycycline hyclate-loaded Eudragit RS-based isg and ism were prepared in this study. The basic properties such as density, pH, surface/interfacial tension of their solvents including dimethyl sulfoxide (DMSO), N-methyl pyrrolidone (NMP), and 2-pyrrolidone (PYR) in Eudragit RS solution and oils (olive oil and camellia oil) were assessed. This research also tested for apparent viscosity of solvent and drug-free and doxycycline hyclate-loaded ERS-based isg and ism, and their phase transformation rates. Density of PYR was higher than that of DMSO whereas these solvents exhibited the less wettability than oils on glass slide. All fabricated doxycycline hyclate-loaded Eudragit RS-based ism formulations showed good emulsion physical stability with no phase separation for 1 hour. The apparent viscosity of ism was significantly less than that of isg. DMSO-based isg and ism exhibited a significantly less viscosity than that of PYR-based formulations. Rapid phase inversion was evident after isg and ism exposure to agarose gel indicating fast solvent exchange. The loose barrier of camellia oil from its less viscosity facilitated a water diffusion inward Eudragit RS-based ism easier than using viscous olive oil. Solvent exchange-induced doxycycline hyclate-loaded Eudragit RS-based ism using DMSO as the solvent and camellia oil as the continuous phase exhibited various appropriate physicochemical characteristics for applying as drug delivery system for periodontitis treatment.