Droplet size and polydispersity index (PDI) of CMF4 microemulsion formulation was measured by 90 plus particle size analyzer (Brookhaven Instruments Corporation, USA). Microemulsion formulation was diluted with deionised milli-Q (Millipore corporation) double distilled water prior to experiment to do away with the effect of viscosity caused on account of emulsion ingredients and also to trim down multiple scattering effect.