Pharma Research Library | Pharma Info Index Research | Innovation | Opportunities |
About author:
Chinmaya Keshari Sahoo*
Research Scholar,Dept. of Pharmaceutics,
OUCT, Osmania University,A.P, India
*e-mail: [email protected]
INTRODUCTION:
Humectants are hygroscopic materials which absorb water vapors from atmosphere till a certain degree of dilution is attained. Aqueous solutions of humectants can reduce the rate of loss of moisture. These are added to cosmetics like oil in water type creams (vanishing cream) to prevent their drying out. Also cosmetics containing humectants are applied on skin, a thin film of humectants is formed which influences texture and condition of the skin. It is for this reason that all moisturizing preparations contain humectants.
Keywords : Humectants, hygroscopic, vanishing cream, cosmetics
DESCRIPTION:
Drying out of cosmetic can occur due to vaporization of water. It depends on temperature, its degree of exposure to air and the relative humidity of air to which the product is exposed. Hence addition of humectants is mostly essential to cosmetic preparations to prevent drying out the products. An ideal humectants characteristics should be
It must absorb moisture from atmosphere and retain the same under the normal conditions of atmospheric humidity.
It should cause a little change only in water content with the change of relative humidity within normal humidity range.
It should be comparative with a large number of raw materials.
It should be colorless or not of too intense color.
It should have good odor and taste.
It should be nontoxic and nonirritant.
It should be noncorrosive to packaging materials which are normally used for packaging of cosmetics.
It should not solidify under normal conditions.
It should not be too costly.
Its viscosity and temperature curve should be relatively flat.
Types of humectants :
There are three types of humectants such as inorganic humectants, metal organic humectants and organic humectants
Inorganic humectants:
These are limited used in cosmetics. Calcium chloride is an example. It has compatibility problems and corrosive in nature. Hence it is not frequently used in cosmetics.
Metal organic humectants:
These are limited used in cosmetics because of compatibility problems, corrosive nature and pronounced taste. The example of this class is sodium lactate. It can be used in skin creams as the lactates occur naturally in the body. So there is no risk of toxicity. An admixture of sodium lactate and lactic acid can be used to overcome PH problems.
Organic humectants:
These are widely used in cosmetics. They include polyhydric alcohols, their esters and ethers. The most commonly used organic humectants are glycerol, ethylene glycol, polyethylene glycol (PEG), diethylene glycol, ethylene glycol, tri ethylene glycol, poly ethylene glycol, propylene glycol, dipropylene glycol, glycerin, polyoxy ethylene glycerin, alpha methyl glycerin, urea, triethanolamine lactate, sorbitol, xylitol, sorbide, poly oxy-ethylene sorbitol, mannitol, glucose, propylene glycol glucoside.
CONCLUSION:
From the above review it can give the idea about humectants and its essentiality of use in cosmetic preparations.
