Doxycycline hyclate-loaded Eudragit® RS PO in situ-forming microparticles for periodontitis treatment

Abstract

At present, in situ-forming microparticles (ISM) containing antibiotic drugs are an alternative formulation for the treatment of periodontitis. In this study, Eudragit® RS PO (ERS) was incorporated in the internal phase of ISM as the matrix-forming agent using dimethyl sulfoxide (DMSO) or 2-pyrrolidone (PYR) as a solvent. Doxycycline hyclate (DH) was chosen as the drug model against periodontal pathogens. Olive oil and camellia oil were used as the external oil phases. The DH-loaded ISM formula presented advantages in terms of injectability over the in situ-forming gel (ISG) owing to the lubricant effect of the outer oil phase and lower viscosity compared with ERS-based ISGs. ISMs containing these two oils exhibited high injectability, suitable phase transformation, and prolonged drug release for 7 days. The obtained microparticles were spherical with a porous structure. Moreover, ISM exhibited effectiveness against periodontal pathogens, which was appropriate for development into local drug delivery to treat periodontitis.