Lotions
Three types of lotions are available. Shake lotions consist of insoluble but hydrophilic powders such as zinc oxide and talc suspended in water. Because they are suspensions rather than solutions they must be shaken prior to use. The soothing effect of a shake lotion depends on the cooling' evaporation of the aqueous vehicle. The powder that remains wicks up moisture from oozing skin surfaces and helps to dry weeping lesions. Unfortunately, shake lotions are messy to use, and repeated applications cause a buildup of zinc oxide under which the damaging effects of maceration occur. Calamine lotion is the only shake lotion used with any frequency today. Pharmaceutical lotions are white, liquid emulsions in which small amounts of oils are suspended in a continuous phase of water. These lotions are typified by the ubiquitous commercially available "hand lotions." Pharmaceutical lotions are primarily used to provide a moderate degree of lubrication in an aesthetically pleasing manner. Pharmaceutical solutions are transparent liquids containing considerable amounts of proglycol and alcohol. They have no lubricating value, but they do dissolve many ingredients not soluble in water and, therefore, are particularly practical for the application of some medications to hairy areas. Pharmaceutical solutions often cause stinging or burning when they are applied to broken skin.
Creams
Creams are semisolid white emulsions too thick to pour from a bottle. For the most part they consist of oils suspended in a continuous aqueous phase. The prototypes of such products are the commercially available "vanishing" or "hand" creams. These preparations are quite useful for lubrication and, because they generally lack a greasy feel, are cosmetically very acceptable.
Ointments
Two types of ointments are available. Hydrophilic ointments are milky white emulsions very pyleness similar in appearance to the creams. They contain moderate amounts of water suspended in a continuous phase of oil. The prototype of such products is rose water ointment (cold cream). These preparations offer very good lubrication but, because they have a somewhat greasy feel, are considerably less cosmetically acceptable than standard creams. Widely used hydrophilic ointments include Polysorb and Aquaphor. A limited amount of water can be added to these ointments. The resultant products, such as Eucerin and Nivea, then appear almost identical with the standard hand creams. Hydrophobic ointments are thick, greasy preparations composed entirely of oils. The prototype of such products is petrolatum (Vaseline). These preparations are extremely good lubricants but are far too greasy for most people to use. These ointments generally lack propylene glycol, preservatives, stabilizers, and other chemical ingredients, and for this reason they rarely cause burning on application or allergic contact dermatitis.
Article Source: http://www.fitnesshealtharticles.com.
About the Author:
Mirror, mirror on the wall, What risks heart disease most of all-high blood pressure or high cholesterol, lack of exercise or too much stress, Type A behavior or a fatty diet, family history or cigarettes? If scientists had the answer, heart disease might not still be our number one killer.
Benefits of Using Lotions and Creams
