Partitioning of Ciprofloxacin in aqueous two-phase system of poly(ethylene glycol) and sodium sulphate

Extraction by an aqueous two-phase system is a powerful technique for separation, concentration, and purification of biomolecules and pharmaceutical products. In the present study, the partitioning of Ciprofloxacin in aqueous two-phase system of PEG-Na2SO4-water has been investigated. The influences of temperature, salt concentration, polymer concentration and polymer molecular weight on the partitioning of Ciprofloxacin were studied. The experiments were designed using an orthogonal central composite design (orthogonal CCD) based on 2(3) full factorial and a second-order model was used to determine the effects of different factors on Ciprofloxacin partitioning. The results of the model indicate that the Ciprofloxacin partitioning is highly dependent on salt concentration. Temperature and PEG concentration have moderate effects on partitioning but PEG molecular weight has no significant effect on the antibiotic partitioning. (c) 2007 Elsevier B.V. All rights reserved.