CPD

• Early Egyptians: first culture to color their hair
• ZHENNA - Red hues
• CHAMOMILE - Blonde Hues
• SAGE - Brown Hues
• William Henry Perkin - synthesized the first non-natural dye

  
• August Hofmann - discovered that

  PARAPHENYLENEDIAMINE (PPD) causes the hair dye to produce color upon exposure to air.
• Melanin a pigment responsible for the coloration of human skin, eyes, and hair
• There are two types of Melanin:

  Eumelanin

  Pheomelanin
• Eumelanin - gives black or brown color

  Pheomelanin - gives red hair or yellow
• p-Phenylenediamine (PPD)

  Foundation of most permanent hair dyes today.

  Mixed with metallic salts for color
• OXIDIZING AGENTS

  Hydrogen Peroxide (H202)
• Hydrogen Peroxide (H202)

  Initiate the color-forming reaction between dye precursors and the developer.
• Ammonia

  -Used to raise the pH of the hair

  -Helps in opening the hair cuticle allowing dye penetration
• Ethanolamine

  -Alternative to ammonia

  -Used to adjust pH in some hair color formulations
• Alkaline agents

  -Ammonia

  -Ethanolamine
• COUPLERS

  Meta-aminophenol (MAP), paraaminophenol (PAP), and orth—aminophenol
• Meta-aminophenol (MAP), para-aminophenol (PAP), and ortho-aminophenol

  Help create specific color shades by reacting with primary dyes during coloring process
• MODIFIERS AND STABILIZERS

  Ethylenediaminetetraacetic acid (EDTA)

  Stabilizers and Preservatives
• Ethylenediaminetetraacetic acid (EDTA)

  -Chelating agent to bind metal ions that might interfere with the color-forming process

  Stabilizers and Preservatives

  -to ensure the stability and shelf life of the hair colorant
• HAIR LIGHTENERS OR BLEACHER

  They work by breaking down the natural pigments in the hair and removing or lightening the melanin, resulting in a lighter hair shade.
• H2O2 -bleaching pigment at alkaline pH value
• Note: 3% H2O2 (I part) is equivalent to 10 volumes
• Ammonium Persulfate and Potassium Persulfate - assist in the oxidation process.
• BLEACHING POWDERS

  Sodium sulphate anhydrous, Light Magnesium Oxide, and Magnesium Silicate
• BLEACHING PASTES

  Made by mixing H202 solution with an absorbent powder immediately before use.
• Liquids and Cream Bleaches

  Generally sold as a two-solution pack: Bottle 1 - 20 or 25 volume of stabilized H2O2; Bottle 2 contains activator
• Activator - contains concentrated soap solution and forms a cream or lotion when mixed with peroxide
• Sodium sulphate anhydrous, Light Magnesium Oxide, and Magnesium Silicate - suitable inert powders used as vehicle for bleach powder or alkali
• Water rinses

  -Mixture of suitable dyestuff with an acid, and are prepared as either powders or liquids.

  -Does not penetrate cortex or medulla and can be removed with a shampoo.

  
• Powdered Form - mixing dyestuff with citric acid or tartaric acid in a sachet or capsule
• Color Shampoos can be regarded into two main groups:

  -Combined in a shampoo base

  -Semi-permanent colorants
• Semi-permanent colorants

  -Give a stronger and more permanent coloration

  -Color effect persists for 6 to 8 subsequent shampoos
• SEMI-PERMANENT COLORANTS

  -The colorants are applied to towel-dried hair after shampooing and allowed to remain on the hair for 20 to 30 minutes to allow maximum absorption of color. Then rinse well the hair with warm water to remove excess color.
• PERMANENT COLORANTS

  -lt can be prepared from materials of vegetable origin, or salts of heavy metals, but those of most commercial importance are the oxidation dyes based on synthetic organic chemicals
• Vegetable dyes (Lawsonia alba or Egyptian privet)
• OHENNA - gives brownish-chestnut shade.

  Application: Powder is made into thin paste with boiling water and brushed into hair while hot with a small stiff brush and combed to ensure even distribution. Hot towels are wrapped around the head and replaced as they cool for half an hour.
• Pyrogallic acid and metallic salts are other additives used with henna powder
• Sensitization Test

  Purpose: Identify allergic reactions and prevent adverse reactions

  
• Selection of Test Area: Behind the ear or Inner Elbow
• Depilatory is an agent for hair removal that is most widely available in cream form.