Equilibrium and kinetics of vancomycin adsorption on polymeric adsorbent

Abstract

Isolation step of vancomycin, a glycopeptide antibiotic, is usually done from fermentation broth filtrate, while its adsorption directly from the whole broth could rationalize the process. The equilibrium and kinetics of vancomycin adsorption from broth supernatant, diluted and whole broth on polymeric adsorbent was studied in this work. Experimental equilibrium data was correlated with Sips, Langmuir, Freundlich, and linear adsorption isotherms. Agreement between measured and regressed data for the first three mentioned models did not vary much and was relatively high. The maximum adsorbed amount for supernatant was higher than for fermentation broths because mycelium particles blocked adsorbent surface. Liquid film mass transfer studies showed that external mass transfer resistance could have been neglected. Diffusion of vancomycin inside adsorbent particles was acknowledged using a nonstructural, homogenous surface diffusion and bidisperse pore models. Model simulations indicated that kinetics of the process could be improved by using smaller adsorbent particles.

Comparison of adsorption equilibrium and kinetic models for a case study of pharmaceutical active ingredient adsorption from fermentation broths: parameter determination, simulation, sensitivity analysis and optimization

“…This resin is an adsorbent for hydrophobic molecules and the AMBERLITE XAD generation of adsorbents was especially designed for both batch and continuous adsorption, having a low density and large particle diameters between 560 and 710 μm (R p = 0.3175 mm). R μ was determined from scanning electron micrograms as 1.69 μm (Likozar et al, 2012).…”

“…Langmuir, Freundlich, Redlich-Peterson, Temkin, Dubinin-Radushkevich, etc., that can be used for biomolecules, e.g. chitosan (Gottipati and Mishra, 2010;Kumar et al, 2010;Piccin et al, 2011), but the Sips model proved to be the best for vancomycin adsorption onto polymeric resin (Likozar et al, 2012).…”

“…A common practice in the modeling of adsorption processes is the use of the kinetic parameters ( 1 k (and 2 k ) or l D , (and D μ )) and the equilibrium parameters for the capacity, reciprocal constant, and order ( max q , D K , (and n )) estimated by nonlinear regression, besides empirical correlations to calculate the transport parameters (liquid phase mass transfer around adsorbent particles was negligible in our case (Likozar et al, 2012)) and batch properties (porosity) in order to simulate the process in a batch. In most cases, the model shows good performance, fitting the experimental data well.…”

“…The development of a mathematical model for the batch vessel adsorption process for vancomycin purification on a hydrophobic-molecule adsorption resin was based on the following hypotheses: (i) The antibiotic concentration at the specific location in the adsorbent pore was in local equilibrium with its concentration adsorbed on the inner surface of the pore wall at the corresponding specific location; (ii) The hydrodynamic behavior of the liquid phase could be neglected as mixing did not have any effect on the adsorption rate (Likozar et al, 2012); (iii) The size distribution of the particles was considered to be the same or different throughout the fluidized adsorbent and the void fraction, depending on the model; (iv) The rheological properties of the crude extract and other media were considered to be the same in all the experiments and independent of the exact concentration;…”

“…Tian et al (2006Tian et al ( , 2008 examined the adsorption on hemofilters in two consecutive studies, while von Winckelmann et al (2009) utilized molecular adsorbents. Scale-up of these processes to an industrial level, however, is probably technologically not viable and therefore preliminary studies were performed by our group using relatively cost-effective polymeric adsorbents (Borin and Pavko, 2009;Likozar et al, 2012).…”