Preparation of water/oil/water type multiple emulsion containing niacinamide for cosmetic purpose

SUMMARYThe aim of this research was to investigate the relation between the composition and the characteristic properties of multiple emulsion(ME) and to observe the effects of oil type and percentage of emulsifiers on the textural characteristics of multiple emulsions. MEs were prepared by a two step emulsification procedure at room temperature. Paraffin, Miglyo818 and the mixture of paraffin and Miglyol were used as an oil phases. AbilEM90 and PluronicF127 were used as lipophilic and hydrophilic emulgators. Niacinamide was used water soluble dermocosmetic substance. MEs were prepared with high content of inner phase. Evaluations the stability of MEs were done by viscometric, conductometric and granulometric methods. Textural properties such as hardness, cohesiveness, consistency and work of shear were measured with different probs. The results indicated that; the nature of oil phase affected the characteristics of MEs. Especially oil polarity played an important role in the transport of niacinamide from internal aqueous phase to external phase. Drug release data indicated that the release of niacinamide entrapped in the internal aqueous phase was slow and the percentage of released amount was less than 60 % for six hours. The effective diffusion coefficient was affected by the concentration of the emulsifiers and oil amount. The more the lipophilic emulgator is increased, the more the release is delayed. The release rate decreased with increasing the amount of hydrophilic emulgator. Viscosities of the MEs were decreased and the electrical conductivity values were increased with time. The results of textural analysis indicated that the emulsifier amount did not exert a significant influence on elasticity, but the amount of hydrophilic emulsifier had little influence on cohesiveness. A negative correlation was found between the hardness and the work of shear. It was concluded that the more work is required in order to elucidate the exact textural properties of MEs.As a result w/o/w MEs containing niacinamide could be formulated using Miglyol or oil Miglyol/liquid parafin mixture. However, further studies are needed to obtain more stable MEs.Key words: Multiple emulsion, niacinamide