Study of Clinical Cosmetology-1: A Hands-on Guide Sonia Tekchandani
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Introduction to Cosmetology1

 
INTRODUCTION
Cosmetology is the science of beautifying the skin and its appendages, which play an important role in sociosexual communication.
Therapeutic cosmetology involves passage of active ingredients across the skin, thereby altering the physiology of the area.
The common cosmetic problems which come to a consultant are acne (pimples), diffuse hair loss, excessive growth of hairs, scars, premature aging of skin, excessive dryness of skin, premature graying of hairs, pregnancy-induced pigmentation on face, etc.
Scientific knowledge of cosmetology enables dermatologist to give rational treatments and aesthetically acceptable results, thereby preventing patient's indulgence in unscientific methods.
 
TERMINOLOGIES IN COSMETOLOGY
Matter: It is anything that occupies space. It exists in 3 forms: Solid, liquid and gas.
Atom: It is the smallest particle of an element. It can take place in a chemical reaction.
pH:
  • pH is a measure of hydrogen ion concentration in dilute aqueous solutions. It is the measure of the acidity or alkalinity of a solution
  • pH level of water is 7.0 at 25°C and defined as ‘neutral’
  • Solutions with pH less than 7 are acidic. Lower the pH, greater the degree of acidity
  • Solutions with pH greater than 7 are basic or alkaline. Higher the pH, greater the alkalinity
  • pH of normal skin is 4.5 to 6 (slightly acidic) due to the secretion of sebum and sweat which act as a protective film against bacterial infection.
Solution: It is a mixture made by dissolving solutes in the solvent.
A solution typically consists of the dissolved material called the solute and the dissolving agent called the solvent. A common example is sugar (the solute) dissolved in water (the solvent).
Dilute solution: It is a solution with small amount of solute in proportion to the quantity of solvent.
Concentrated solution: It is a solution which contains large quantity of solute in proportion to the quantity of solvent.
Saturated solution: A saturated solution is a solution containing the maximum concentration of a solute at the given temperature. Additional solute will not dissolve in a saturated solution at that given temperature.
Suspension: It is a temporary mixture of insoluble powder in liquid. For example, sand in water, calamine lotion, etc.
They are typically clear products with visible particles like gelatin beads or inorganic minerals (e.g. titanium dioxide) suspended throughout. They are used for sunscreens, hand washes, shampoos, etc.2
Emulsions: It is a permanent mixture of 2 or more unmixable liquids united and stabilized by an emulsifier. They are used for products like hand moisturizers, make-up, hair conditioners, sunscreens, etc. To create them, you need three formula components including an oil phase, aqueous phase and an emulsifier. The formulas are made by heating up the oil and water phases separately, mixing them together (along with the emulsifier) when they are hot, and cooling them down with thorough mixing the following:
  • Oil in water (o/w): Emulsion made of oil droplets dispersed in watery base. Due to higher water content, it is often an easy flowing liquid or milk.
  • Water in oil (w/o): Emulsion is made up of water droplets scattered within the oily base. For example, cold cream, cleansing creams, etc.
Humectants: It is a natural content present in products that has the ability to attract and retain water to itself. These substances are called hygroscopic, which means that they are able to absorb ambient water. For example, glycerine present in lotions, hand creams, humectant in food products is sorbitol. This humectant is a sugar alcohol-derived from sugar.
A humectant like mineral oil, however, can actually build up under the skin and prevent the skin from absorbing essential vitamins and nutrients. It gives a velvety feel to the skin. Humectants are derived from cherries, plums, pears, apples and seaweed.
Soybean oil: A vitamin-rich emollient that absorbs well into the skin. It has a nourishing, softening and moisturizing effect on skin. Propylene glycol is generally used as a humectant.
Collagen: Collagens have great tensile strength, and provide these body structures with the ability to withstand forces that stretch them.
Acids: Acids have pH less than 7. They are sour to taste. Acid neutralizes bases producing salt and water. For example, HCl.
Bases alkalis: Bases have pH more than 7. They are bitter to taste. Bases turns red litmus to blue. Acid neutralizes bases producing salt and water. For example, NaOH.