Thawatchai Phaechamud
Silpakorn University, Thailand
Title: Solvent exchange-induced in situ forming gel comprising eudragit RS-antimicrobial drugs
Biography
Biography: Thawatchai Phaechamud
Abstract
Eudragit RS (ERS), a quaternary polyacrylate positively charged polymer, exhibits a very low permeability and swells in aqueous media independently of pH without dissolving. Owing to its high solubility in N-methyl pyrrolidone (NMP) it was interesting to apply as polymer matrix for solvent-exchanged in situ forming gel which this drug delivery system was in sol form and transforming into solid-like after injection and exposure to the aqueous fluid of the body. The aim of this research was to study the parameters affecting the gel properties, drug release and antimicrobial activities of the in situ forming gels prepared from Eudragit RS dissolved in NMP to deliver the antimicrobial agents (doxycycline hyclate, metronidazole and benzyl peroxide) for periodontitis treatment. The solvent exchange between NMP and an external aqueous simulated gingival crevicular fluid stimulated the dissolved Eudragit RS transforming into the opaque rigid gel. Doxycycline hyclate, metronidazole and benzyl peroxide loaded-ERS systems exhibited Newtonian flow which their syringeabilities were acceptable. The higher-loaded Eudragit RS promoted the more prolongation of drug release because of the retardation of water diffusion into the precipitated matrix. Antimicrobial activities against Staphylococcus aureus, Escherichia coli, Candida albicans, Streptococcus mutans and Porphyrommonas gingivalis depended on type of drugs and test microorganisms. Doxycycline hyclate loaded-Eudragit RS systems showed these activities greater than the others however all of them could inhibit the all test microorganisms. Thus the solvent exchange-induced in situ forming gels comprising Eudragit RS-antimicrobial drugs exhibited potential use as localized delivery systems for periodontitis treatment