Preparation, characterization and in vitro release study of carvacrol-loaded chitosan nanoparticles

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 84; no. 1; pp. 163 - 171
• Main Authors: Keawchaoon, Lalita, Yoksan, Rangrong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2011
• Subjects: acetates; Anti-Infective Agents - chemistry; Anti-Infective Agents - pharmacology; anti-infective properties; Antimicrobial activity; Bacillus cereus; Bioactive compound; Buffer solutions; Carvacrol; Charged particles; Chitosan; Chitosan - chemistry; colloids; Controlled release; Drug Carriers - chemistry; Emulsions; Emulsions - chemistry; encapsulation; Escherichia coli; Gelation; Gels - chemistry; Hydrogen-Ion Concentration; Media; Microbial Sensitivity Tests; Models, Biological; Monoterpenes - chemistry; Monoterpenes - pharmacology; Nanoparticles; Nanoparticles - chemistry; Particle Size; Staphylococcus aureus; Surface chemistry; tripolyphosphates; zeta potential; Nanoparticles; Carvacrol; Bioactive compound; Antimicrobial activity; Chitosan; Controlled release
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2010.12.031

[Display omitted] ▶ Carvacrol-loaded chitosan particles were prepared through emulsion formation and ionic gelation. ▶ Particles exhibited spherical shape, 40-80nm-size and positively charged surfaces. ▶ Particles showed antimicrobial activity against S. aureus, B. cereus and E. coli. ▶ Release of carvacrol in an acidic solution was faster than alkaline and neutral media. 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 0.25–1.25g/g of chitosan. The individual particles exhibited a spherical shape with an average diameter of 40–80nm, and a positively charged surface with a zeta potential value of 25–29mV. 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 0.257mg/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.