Reverse micelle liquid–liquid extraction of a pharmaceutical product

Reverse micelle extraction has received considerable attention in recent years due to its ability to selectively solubilise solutes from an aqueous phase, and in the case of biomolecules to maintain their biological activities, This thesis reports the results from studies on the extraction of penicillin G from aqueous solution (forward extraction) and from the reverse micelle to a new aqueous solution (backward extraction), The extraction is influenced by the initial penicillin G concentration, the salt type and concentration in the aqueous phase, pH, and surfactant concentration. The results show that penicillin is an interfacially active compound that interacts with AOT, with the interfacial association being dependent on both pH and surfactant concentration. When the penicillin to surfactant concentration ratio [P]aq/[S] is high precipitation of the penicillin occurs. The distribution coefficient favours transfer of the penicillin into the reverse micelle at moderate AOT concentrations.