title: Preparation, characterization and in vitro release study of carvacrol-loaded chitosan nanoparticles.
abstract: The fabrication of carvacrol-loaded chitosan nanoparticles was achieved by a two-step method, i.e., oil-in-water emulsion and ionic gelation of chitosan with pentasodium tripolyphosphate. The obtained particles possessed encapsulation efficiency (EE) and loading capacity (LC) in the ranges of 14-31% and 3-21%, respectively, when the initial carvacrol content was 0.25-1.25 g/g of chitosan. The individual particles exhibited a spherical shape with an average diameter of 40-80 nm, and a positively charged surface with a zeta potential value of 25-29 mV. The increment of initial carvacrol content caused a reduction of surface charge. Carvacrol-loaded chitosan nanoparticles showed antimicrobial activity against Staphylococcus aureus, Bacillus cereus and Escherichia coli with an MIC of 0.257 mg/mL. The release of carvacrol from chitosan nanoparticles reached plateau level on day 30, with release amounts of 53% in acetate buffer solution with pH of 3, and 23% and 33% in phosphate buffer solutions with pH of 7 and 11, respectively. The release mechanism followed a Fickian behavior. The release rate was superior in an acidic medium to either alkaline or neutral media, respectively.
authors.affiliation: Department of Packaging and Materials Technology, Faculty of Agro-Industry, Kasetsart University, Bangkok, Thailand.
authors.forename: Lalita
authors.initials: L
authors.lastname: Keawchaoon
authors.forename: Rangrong
authors.initials: R
authors.lastname: Yoksan
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology; D048271:Chitosan / Q000737:chemistry*; D000081007:Cymenes; D004337:Drug Carriers / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry; D005782:Gels / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008826:Microbial Sensitivity Tests; D008954:Models, Biological; D039821:Monoterpenes / Q000737:chemistry* / Q000494:pharmacology; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size
chemical_list: D000890:Anti-Infective Agents; D000081007:Cymenes; D004337:Drug Carriers; D004655:Emulsions; D005782:Gels; D039821:Monoterpenes; D048271:Chitosan; C073316:carvacrol