Drug transport mechanisms and in vitro release kinetics of vancomycin encapsulated chitosan-alginate polyelectrolyte microparticles as a controlled drug delivery system

Abstract

In this study, chitosan-alginate polyelectrolyte microparticles containing the antibiotic, vancomycin chloride were prepared using the ionotropic gelation (coacervation) technique. In vitro release and drug transport mechanisms were studied concerning the chitosan only and alginate only microparticles as a control group. Further, the effect of porosity on the drug transport mechanism was also studied for chitosan-alginate mixed particles produced by lyophilizing in contrast to the air-dried non-porous particles. According to the in vitro release data, alginate only and chitosan only microparticles showed burst release and prolonged release respectively. Chitosan-alginate lyophilized microparticles showed the best-controlled release of vancomycin with the average release of 22μg per day for 14days. Also, when increasing alginate concentration there was no increase in the release rate of vancomycin. The release data of all the microparticles were treated with Ritger-Peppas, Higuchi, Peppas-Sahlin, zero-order, and first-order kinetic models. The best fit was observed with Peppas-Sahlin model, indicating the drug transport mechanism was controlled by both Fickian diffusion and case II relaxations. Also, Fickian diffusion dominates the drug transport mechanism of all air-dried samples during the study period. However, the Fickian contribution was gradually reducing with time. Porosity significantly effects the drug transport mechanism as case II relaxation dominates after day 10 of the lyophilized microparticles.

Production and Characterization of Chitosan–Polyanion Nanoparticles by Polyelectrolyte Complexation Assisted by High-Intensity Sonication for the Modified Release of Methotrexate

“…The ratio of the relaxational to the diffusional behavior (R/F) of NPs is depicted in Figure 6. Except for MTX-PAM-2Na, the diffusional component prevailed for most NPs [70]. Further, NPs produced with PAM-18 showed the largest diffusional contribution to MTX release, showing the largest drug retention, whereas NPs produced with PAM-2 anions showed more relaxation/gelling contribution, easing drug release.…”

<p>The Oral Administration of Lidocaine HCl Biodegradable Microspheres: Formulation and Optimization</p>

“…24 More recently, alginatechitosan loaded drugs have been developed to improve the bioavailability of a large number of drugs. [19][20][21][22][23][24]26,27 Mean Particle Size, Poly Disparity Index, and Zeta Potential…”

“…41 In addition, the observed pH-dependent pattern was consistent with the previously described drug release behavior of indomethacin-crosslinked chitosan-Malginate microspheres, in which a higher pH caused lower rates of indomethacin release due to greater crosslinking in the microspheres. 27 Protonation of the amine groups of the drug is known to improve solubility in an acidic medium. At low pH, alginate and chitosan are known to exist in a gel form, while at neutral pH, the viscous complex will swell and the gel will slowly disintegrate, thus causing the drug to be released.…”

“…The same relationship between drug loading and the rate of release was observed in a previous study. 27,44…”

Polyelectrolyte nanocontainers: Controlled binding and release of indomethacin

“…To study the indometacin release from capsules the kinetic model of Ritger -Peppas [56] has been used. This simple semi-empirical model is fully sufficient for spherical delivery systems [57][58][59] and given by equation: is a constant incorporating structural and geometric characteristics of the particles, and n is the release exponent, indicative of the mechanism of drug release. In the case of spherical delivery systems when n = 0.43 drug release mechanism is Fician diffusion.…”