PROLONGED RELEASE OF DICLOFENAC SODIUM FROM MULTIPLE W/O/W EMULSION SYSTEMS

Multiple emulsions contained diclofenac sodium (1) were prepared and evaluated for in vitro characterization. The effect of pH of internal and external aqueous phases on the release of drug was studied. The partition coefficient of 1 between an internal aqueous phase (at variable pH) and isopropylmyristate (IPM) [oily phase] was determined and its effect on the release profile was elucidated. It has also been observed that the release rate of 1 contained in the internal phase increases significantly on the addition of calcium stearate and soya lecithin in middle organic/oily phase.