Considering the therapeutic effects of formulations with violate essential
oils, development of an available drug delivery system is of great interest,
especially assuming the fact that using essential oils as antimicrobial
agents is a rather expanded in antimicrobial therapy nowadays. In this work,
chitosan microparticles with encapsulated thyme essential oil were prepared
by the emulsion 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 from 4.71?1.42 to 13.65?4.34 m, 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, 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.