Kinetic study of antibiotic by reverse micelle extraction technique

Abstract

The kinetic reverse micelle extraction of penicillin G was studied using the new surfactant; dioleyl phosphoric acid. Studies were conducted for model development on the kinetic partitioning of penicillin G and for investigation of mechanism governing the forward and backward transfers of penicillin G in reverse micelle system. Results were interpreted in terms of a two-film theory for flat interface. The extraction in this system was found to be controlled by interface solubilization and the diffusion of the penicillin G in the aqueous phase boundary layer. The values mass transfer coefficient of forward extraction, KLA increased from 0.2859 × 107 to 0.6115 × 107 as the aqueous pH was increased from 5 to 8. While as dioleyl phosphoric acid concentration increased from 5 mM to 10 mM, the value of KLA and forward extraction equilibrium partition coefficient, mf were increased from 0.1285 × 107 to 0.8971 × 107 and 0.4954 to 1.40085 respectively. However further increased dioleyl phosphoric acid concentration up to 25 mM the value of KLA and mf were declined because the organic solution becomes saturated with dioleyl phosphoric acid molecules. From the experimental result it was found that the transfer rate and efficiency was reduced dramatically at higher concentration of salt and an increase of penicillin G concentration the driving force between charge polar heads of dioleyl phosphoric acid and opposite charge of penicillin G molecules.