Multiple emulsion based systems for prolonged delivery of rifampicin: in vitro and in vivo characterization

Multiple emulsions containing rifampicin were prepared and evaluated for in vitro and in vivo performance. The effect of pH of internal aqueous phase on the in vitro and in vivo release profile of rifampicin were studied. The partition coefficient of rifampicin between internal aqueous phase and isopropyl myristate was determined. The effect of aqueous phase pH on the partition coefficient and its resulting effect on the release profile was elucidated. The plasma level observed implicated that the multiple emulsion gave prolonged drug release.