Study Of The P/O/W Multiple Emulsions And Its Application Of Encapsulating Vitamin C

Multiple structure is a special structure with wild application in cosmetics.Polyols-in-oil-in-water(P/O/W)multiple emulsions was prepared by using polyols as the inner aqueous phase which can not only offer great skin feeling,but also solve the application limitation induced by water.Firstly,P/O/W emulsions which can keep stable for two months at room temperature were prepared by studying the preparation process and formula compositions.Results shown that the optimal preparation process are: homogeneous power is 15500r/min,homogeneous temperature is 70-80?,the homogeneous time of P/O emulsions is 2 min,the homogeneous time of P/O/W emulsions is 3 min.The optimal formula compositions are: glycerol,Cetyl PEG/PPG-10/1 Dimethicone,mineral oil and block copolymer Poloxamer 407.Secondly,the intermiscibility of oils and emulsifiers and different phase rate were investigated to study their effects on the formation and stability of the system.Studied shown oils which have similar solubility parameters with the hydrophobic group of emulsifiers will benefit for system stability.Proper phase rate is important for the formation of stable system.The optimal oil-polyol rate is 10:5 and the polyols in oil – water rate is 1:4 or 1:5.Finally,Vitamin C was encapsulated with the new kind of multiple emulsions.The influences of formulation factors,including concentration of lipophilic emulsifiers,hydrophilic emulsifiers,salts and glycerol had been investigated.Also,the encapsulation stability and permeability of P/O/W emulsions and W/O/W emulsions were studied.The results obtained indicate that the encapsulation stability could be improved by increasing the lipophilic emulsifier concentration while could be reduced with excess hydrophilic emulsifier.The presence of glycerol in the outer aqueous phase seemed accelerate the phase transfer,thus reduced the encapsulation rate.The addition of salt in inner polyols phase can not only improve the homogeneity of particles,but also improve encapsulation rate.P/O/W multiple emulsions showed better encapsulation stability than the W/O/W multiple emulsions while they have similar permeability.