DIAS, G.; http://lattes.cnpq.br/0096282519277341; DIAS, Geceane.
Résumé:
The proposal to use a controlled release system as an alternative to conventional
treatments aimed at administering antibiotics has gained strength in recent decades.
The chitosan-based hydrogel, an antimicrobial biopolymer, offers the possibility of
controlling the release of the drug when it is cross-linked by agents such as genipin.
However, knowledge about the characteristics involved, such as the rate and mass
transport mechanisms, involved in the controlled release of vancomycin in chitosan
hydrogel is still limited. Given the above, the objective of this work is to synthesize a
polymeric chitosan / genipin matrix to evaluate the characteristics regarding the rate
and the mechanisms of mass transport involved in the control of vancomycin release
over time. For this purpose, an aqueous solution of chitosan 1.5% (w/v) in lactic acid
was prepared, keeping under stirring on a magnetic stirrer and for comparison
purposes the addition of the crosslinking agent genipin and the drug vancomycin was
performed by three procedures: the first was adding vancomycin together with
genipin (H1), and the second and third method was adding vancomycin before
crosslinking (H2), and after crosslinking the base solution (H3). The samples were
characterized by Fourier transform infrared spectroscopy (FTIR); X-ray diffraction
(XRD), and thermogravimetric analysis (TG) and finally, the vancomycin release test
in the hydrogel, analysis of variance (ANOVA) and the Tukey test or t test with a 5%
probability significance were performed with the help of the statistical software PAST
version 3.23 (Hammer et al., 2001) and mathematical models. Based on the results it
was possible to observe that the FTIR spectra showed the characteristic bands of the
studied materials. The XRD diffractograms confirmed the formation of the semi-
crystalline phases of chitosan and crystalline of the genipin. Vancomycin proved to
be amorphous. Through the results obtained in the thermogravimetric analyzes, it
was possible to observe thermal behaviors characteristic of the studied materials.
Confirmed by the appearance of events that are characteristic of mass changes in
the material upon exposure to temperature. Through the kinetic profile of the
vancomycin drug release, it can be observed that the release occurs more quickly at
the beginning, up to 150 minutes, and that then this release becomes slower until the
end of the observed time of 300 minutes. From the analysis of variance (ANOVA)
and the Tukey test, it was possible to observe that the order in which vancomycin is
added to the hydrogel carrier system is not a major factor in altering or modifying the
final quantity released, as well as the storage period. Regarding the study of drug
release kinetics, it predicted a Fickian mechanism based on diffusion. We can
conclude that from the tests carried out, that the use of a carrier system based on
chitosan and genipin for controlled release of vancomycin occurs promisingly, since it
will possibly prevent adhesion, colonization and subsequent bacterial proliferation.
