Development of an available drug delivery system is of great interest considering the
therapeutic effects of formulations with violate essential oils, especially assuming the fact
that using essential oils as antimicrobial agents is a rather expanded in antimicrobial therapy
nowadays. In this paper, the chitosan microparticles with encapsulated thyme essential
oil were prepared in the emulsion by cross-linking method. The effect of thyme oil and
glutaraldehyde initial concentrations on particle size, morphology, and particle size distribution
was investigated. In addition, the influence of these parameters on the encapsulation
of thyme oil in chitosan microparticles, concerning thyme oil loadings and encapsulation
efficiency was also tested. The particles showed a spherical shape with an average
diameter of 4.71±1.42 to 13.65±4.34 μm, depending on the concentration of the essential
oil and glutaraldehyde that were used. The diameter of microparticles appeared to increase
with increasing the thyme essential oil concentration, and decreased with the increase
of glutaraldehyde concentration. It was shown that the concentration of glutaraldehyde
did not affect the degree of encapsulation, but the increase in the initial concentration
of thyme oil increased the degree of encapsulation of this essential oil in chitosan
microparticles. All particles containing thyme essential oil, as well as essential oil of thyme
itself showed significant antimicrobial activity against Staphylococcus aureus ATCC 25923,
Esherichia coli ATCC 25922, Candida albicans ATCC 24433 and Enterococcus faecalis ATCC
25929. This study showed a great potential of the use of thyme essential oil as an antimicrobial
agent, especially when encapsulated in a drug delivery system with controlled
release of the active antimicrobial component.