![]() Stearic acid creams (sometimes called vanishing creams) are o/w emulsions and have a semisolid consistency but are only 15% internal phase volume. the internal phase volume to external phase volume ratio.The consistency of emulsions varies from easily pourable liquids to semisolid creams. They are intended to be used in areas where the skin rubs against itself such as between the fingers, thighs, and under the arms.Įmulsions are also used an ointment bases and intravenously administered as part of parenteral nutrition therapy. The term “lotion” is not an official term, but is most often used to describe fluid liquids intended for topical use. Emulsions are also the bases used in lotions, as are suspensions. They can be either o/w or w/o and are generally opaque, thick liquids or soft solids. Topical emulsions are creams which have emollient properties. More typically, emulsions are used for topical administration. But sometimes, emulsions are the formulation of choice to mask the taste of a very bitter drug or when the oral solubility or bioavailability of a drug is to be dramatically increased. Oral administration can be used, but patients generally object to the oily feel of emulsions in the mouth. ![]() W/O emulsions are generally formed if the aqueous phase constitutes < 45% of the total weight and a lipophilic emulsifier is used.Įmulsions are used in many routes of administration. ![]() Conversely, where water or aqueous solutions are dispersed in an oleaginous medium, the system is known as a water-in-oil (w/o) emulsion. An o/w emulsion is generally formed if the aqueous phase constitutes > 45% of the total weight, and a hydrophilic emulsifier is used. Where oils, petroleum hydrocarbons, and/or waxes are the dispersed phase, and water or an aqueous solution is the continuous phase, the system is called an oil-in-water (o/w) emulsion. ![]() The dispersed liquid is known as the internal or discontinuous phase, whereas the dispersion medium is known as the external or continuous phase. The effects of different oil phases used in the formulation on the physical characteristics and stability of the emulsion.Īn emulsion is a thermodynamically unstable two-phase system consisting of at least two immiscible liquids, one of which is dispersed in the form of small droplets throughout the other, and an emulsifying agent.The effects of HLB surfactant on the stability of the emulsion. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |