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.

-Mathematical models for a batch process were developed to predict concentration distributions for an active ingredient (vancomycin) adsorption on a representative hydrophobic-molecule adsorbent, using differently diluted crude fermentation broth with cells as the feedstock. The kinetic parameters were estimated using the maximization of the coefficient of determination by a heuristic algorithm. The parameters were estimated for each fermentation broth concentration using four concentration distributions at initial vancomycin concentrations of 4.96, 1.17, 2.78, and 5.54 g l −1 . In sequence, the models and their parameters were validated for fermentation broth concentrations of 0, 20, 50, and 100% (v/v) by calculating the coefficient of determination for each concentration distribution at the corresponding initial concentration. The applicability of the validated models for process optimization was investigated by using the models as process simulators to optimize the two process efficiencies.

A mathematical model of the continuous fixed-bed column adsorption process for isolation of the glycopeptide antibiotic vancomycin, which is an active ingredient in pharmaceutical drugs, from a fermentation broth filtrate on two different polymeric adsorbent resins (Amberlite XAD16N and 1600N) was developed and validated by laboratory-scale experiments. The model was utilized for the prediction of breakthrough curves and, consequently, dynamic adsorption capacities by the application of independently determined adsorption equilibrium and intraparticle kinetic data obtained from batch experiments and hydrodynamic parameters in order to analyze the column performance. The application of structural adsorption/desorption kinetics, taking into account the resin particle size distribution, improved agreement between the calculated and measured data much more than by varying the effect of external mass transfer. A parametric sensitivity analysis of the model was also performed. The study showed that the use of XAD1600N is advantageous in terms of process economics, as the dynamic adsorption capacity is ∼2.5−3.0 times higher, compared to that for XAD16N.

Reverse osmosis to concentrate the lisinopril after a low-pressure liquid chromatography was tested under various process conditions on a pilot-scale unit. It was found that the permeate flux 20−30 L/hm2 can be kept over the whole concentration range with a feed pressure up to 35 bar and that fouling is negligible. The rejection of lisinopril is almost complete. These data were used for a conceptual design and installation of an industrial scale reverse osmosis unit with the membrane surface area 60 m2 and capacity of 1.5 m3/h permeate. The capital cost estimate is significantly lower compared to a single-stage vacuum evaporator. The operating cost estimate for evaporation is roughly $6.8/kg lisinopril, while the estimated cost for concentration of lisinopril solution with reverse osmosis taking into account the theoretical energy consumption by pumps is $0.23−0.33/kg lisinopril. Cost calculated from actual plant data is even lower, $0.16/kg lisinopril. The validation results of the full-scale unit and its trouble-free operation prove that the decision for reverse osmosis is economically justified and that the scale-up was technically successful.