Ammonium and manganese sulfate salts vs. Brij 35 in forming new aqueous biphases: Application in validation of drug-drug interaction

Aqueous solution of a nonionic surfactant Brij 35 has been used against two sulfate salts, ammonium sulfate and manganese sulfate to construct new aqueous biphasic systems (ABS). Well defined phase diagrams with suitable tie-lines were obtained by turbidometric titration method at 303 K. The tie-line lengths and slope of the tie lines were calculated and the results were validated using Othmer-Tobias and Bancroft equations. The newly designed systems have been used to extract two different drugs ciprofloxacin and ibuprofen. Binary extraction of the two drugs in the ABS indicates a possible interaction between the two biomolecules which were further verified by kinetic spectrophotometric study, CD spectra and ESI MS. Results of binary extractions of two drugs in an ABS can act as a platform to identify molecular interactions, drug-drug interactions in this case which is an upcoming application of ABSs.