Thursday, May 19, 2011

CREAMS AND LIQUID EMULSIONS FOR FACIAL CLEANSING VS. SOAP

Makeup preparations, especially those based on heavy oils, are removed from the skin more easily using cleansing creams or emulsions, which have a relatively high fat content compared with normal soap. Cleansing creams and emulsions dissolve the fatty substances (which contain the makeup pigments), making removal of makeup easier. These substances are more effective at removing sebum from the skin than soap and water.

Since cleansing creams and emulsions contain oils, a thin layer of oil may still remain on the skin after rinsing them off. For this reason, these preparations are generally more effective for people with dry skin and are not usually recommended for people with oily skin or acne. Nevertheless, many cleansing creams and preparations are manufactured in a range of variations, as subgroups of the original product, designated specifically for use with dry, normal, or oily skin—depending on the customer’s requirements.

Cleansing creams and emulsions are usually made of relatively delicate cleansing agents (compared with the wide variety of soaps and “soapless” soaps). If they are rinsed off with water after use (not just wiped off), their cleansing effect is gentler and usually does not cause skin irritation.

SOAPS FOR USE IN ACNE

Some of the soaps intended for use in acne contain antibacterial substances such as benzoyl peroxide. Benzoyl peroxide is a strong oxidizing agent that penetrates the hair follicle and acts on the bacteria that are involved in the development of acne. The other soaps intended for use in acne are mainly those designed for use on oily skin, which have very potent cleansing properties. Reducing the oiliness of the skin may help in the treatment of acne. Note, however, that most of the medical preparations used nowadays in the treatment of acne may dry out the skin. This, in addition to excessive use of soaps that also tend to dry out the skin, can lead to extremely dry skin.

Antibacterial Substances

“Antibacterial” soaps usually contain triclocarban and triclosan. Residues of these substances remain on the skin surface after washing, thereby inhibiting the growth of bacteria. Soaps that contain antibacterial substances are used mainly to prevent unpleasant body odors. They are also used for several types of superficial skin infections such as folliculitis (infection of the hair follicles), or acne, as well as following exposure to dirt or any other potential source of contamination.

Fragrances and Perfumes

It is common practice in most cosmetic preparations, including soap, to add scents of various types to hide the odors of the raw ingredients used. Sometimes these substances can cause allergic reactions.

Transparent Soap

Transparent soap represents another type of soap which contains moisturizers. These soaps usually contain a higher than usual concentration of glycerine or various sugars. The high glycerine content gives the soap its transparent appearance. Some dermatologists maintain that glycerine tends to absorb water contained in the skin, causing these soaps to have a drying effect in certain cases. For this reason, some transparent soaps contain additional moisturizing agents; hence each transparent soap can be tailored specifically for dry, normal, or oily skin. In general, transparent soaps are considered to be relatively mild.

Soaps Meant for Use on Oily Skin

surfactants that are particularly effective in removing the oily layer from the skin. In general, the use of moisturizing agents should be tailored to the type of skin: someone with dry skin needs a soap that contains moisturizing agents. On the other hand, there is no need (and indeed it is unwise) for someone with oily skin, or someone with acne, to use moisturizing soap. Some dermatologists claim that liquid soaps tend, more than bar soaps, to dry out the skin. Therefore, it would be desirable, for those suffering from dry skin, to minimize their use.

POSSIBLE DISADVANTAGES OF REGULAR SOAP

Normal tap water contains calcium and magnesium. When ordinary soap is used with tap water, calcium and magnesium salts of fatty acids are formed. These are “sticky,” not readily soluble salts. The salts remain on the skin surface and may lead to skin irritation.

Another reason regular soap may cause skin irritation is that it has a high pH. The pH of regular soap lies between 9 and 10 (and sometimes higher than 10)—much higher than the normal skin pH (which is between 4 and 6.5). Consequently, it raises the skin’s pH (see below for an explanation of the concept of pH). However, healthy skin has mechanisms for adjusting its pH, so that shortly after it has been exposed to regular soap, its level of acidity returns to normal. (The pH returns to normal any time from half an hour to two hours after soap has been used.) Nevertheless, in some people, abrupt changes in pH can cause significant skin irritation. Therefore, the current trend in the cosmetics industry is to adapt the pH of cleansing agents and other cosmetic preparations to that of normal skin.