Hair dyes

Hair Dyes
Dr. Prashant L. Pingale
Associate Professor,
Dept. of Pharmaceutics,
GES’s Sir Dr. M. S. Gosavi College of Pharm. Edu. and Research,
Nashik-422005

History of Hair colors
• Early Egyptians used the first hair color.
• First culture to color hair
• Used:
– Henna- Red hues
– Chamomile- Blonde Hues
– Sage- Brown Hues

• Red hair was popular due to:
Queen Elizabeth’s red hair.
Women would:
– Apply mixture of black sulfur, alum,
and honey and sit in the sun until the
hair has turned a golden.

• Late 1800’s
Paraphenlylenediame
– Chemical base for hair color
– Mixed with metallic salts for color
• Metallic salts are a combination of copper, lead,
silver, and other metals with a weak acid

Early 20th
Century
• Popular for actresses to
color their hair.
• It wasn’t until the middle
of the century that a
common woman dying her
hair was accepted.

Reasons for hair color
• To change the natural color of the hair,
• To color the grey hair,
• To change the color of the hair temporarily
for a particular occasion

Ideal characteristics of hair colors
• Color hair without reducing natural gloss
• Not change the texture of hairs
• Not injure hair shaft
• Non-irritant & free from sensitization
• Not have systemic toxicity
• Color of dyed hair: stable to physical factors
• No effect of shampoos, brilliantines, setting lotions on the
dyed hair.
• Stable in the formulation sold in market

RAW MATERIALSRAW MATERIALS
• Differ from manufacturer to manufacturer.
• In general, hair dyes include dyes,
– modifiers,
– antioxidants,
– alkali,
– soaps,
– ammonia,
– wetting agents,
– fragrance,
• A variety of other chemicals used in small amounts that impart special
qualities to hair (such as softening the texture) or give a desired action
to the dye (such as making it more or less permanent).
• Dye chemicals are usually amino compounds.

RAW MATERIALSRAW MATERIALS
• Other chemicals used in hair dyes act as modifiers, which
stabilize the dye pigments or otherwise act to modify the
shade.
• The modifiers may bring out color tones, such as green or
purple, which complement the dye pigment. e.g. resorcinol
• Antioxidants protect the dye from oxidizing with air. Most
commonly used is sodium sulfite.
• Alkali are added to change the pH of the dye formula,
because the dyes work best in a highly alkaline composition.
Ammonium hydroxide is a common alkali.

Types of hair colors
• Temporary hair color
• Semi permanent hair color
• Permanent hair color

Temporary hair color
• Temporary hair color is available in various product forms including
rinses, shampoos, gels, sprays, foams.
• This type of hair color is typically used to give brighter, more vibrant
shades or colors such as orange or red, that may be difficult to achieve
with semi-permanent and permanent hair color.
• While temporary hair color products hold a lesser market than semi-
permanent and permanent agents, they have value in that they can be
easily and quickly removed without bleaching or application of a
different coloring product.
• These colorants do not penetrate into cortex or medulla.
• As such the dye is easily removed with shampoo so known as
temporary hair color

Semi permanent hair color
• Differ form color shampoo with respect to time
• Give stronger & more permanent coloration to hair
• Some colors are removed in 4-8 shampooings.
• Dyes used are:
– Ntirophenyledenediamine,
– Nitroaminopheols,
– Aminoanthraquinones.
• Mixture is prepared before preparing color shades.
• Should be studied on white wool or hair.
• Semi hair color has no Ammonia.

Permanent color
• All "permanent" haircolor products and lighteners contain both a
developer, or oxidizing agent, and an alkalizing ingredient as part of
their ammonia or an ammonia substitute.
• The purpose of this is to:
– raise the cuticle of the hair fiber so the tint can penetrate,
– facilitate the formation of tints within the hair fiber,
– bring about the lightening action of peroxide.
• When the tint (color) containing the alkalizing ingredient is combined
with the developer (usually hydrogen peroxide), the peroxide becomes
alkaline and diffuses through the hair fiber, entering the cortex, where
the melanin is located.
• The lightening occurs when the alkaline peroxide breaks up the
melanin and replaces it with new color.

• Permanent hair-coloring products consist of two components
that are packaged separately and mixed together immediately
before application.
• One package contains a solution of hydrogen peroxide
(usually 6%) in water or a lotion base.
• The other package usually contains an ammonia solution of
dye intermediates and preformed dyes—called couplers.

• Now a days, plant materials are used e.g. henna leaves
• Infusions, decoctions of plant materials are used.
• The paste of powder of henna leaves prepared in hot water
• After cooling it is applied with stiff brush & allow to dry.
• Henna contains lawsone (2- hydroxy- 1,4- napthoquinone)

• Advantages of henna:
– Non-toxic,
– Non sensitizing to skin
• But laborious work to prepare henna paste
• Following composition is generally used nowadays:
Powdered henna 89%
Pyrogallic acid 6%
CuSO4 5%
• Concentration of pyrogallic acid responsible for color

Dye intermediates in semi-permanent
hair dyes
Shades Name of dye intermediate
Yellow 4 - nitro- m- phenylene diamine
Orange 2 - amino- 4- nitrophenol
Red 4 - (2- hydroxy ethyl) amino- 3- nitrophenol
Violet 1 – 4 - diamino-5- nitro- anthraquinone

Dye intermediates in permanent hair dyes
• Oxidation bases:
– p- phenylene diamine,
– p- toluenediamine,
– p- amino diphenylamine,
– p- aminophenol,
– p- diamino anisole,
– o- phenylene diamine,
– o- aminophenol

THE MANUFACTURINGTHE MANUFACTURING
PROCESSPROCESS
• Checking ingredients
• Weighing
• Pre-mixing
• Mixing
• Filling

PROCESSPROCESS
Checking ingredients
• Before a batch of hair dye is made, the ingredients
must be certified.
• Certification may be done by the manufacturer in-
house.
• In many cases, the ingredients arrive from a reputable
vendor who has provided a CoA and this satisfies the
manufacturer's requirements

PROCESSPROCESS
Weighing
• Next a worker weighs out the ingredients for the batch.
• For some ingredients, only a small amount is necessary in the
batch.
• But if a very large batch is being made, and several ingredients
are needed in large amounts, these may be piped in from
storage tanks.

PROCESSPROCESS
Pre-mixingPre-mixing
• In some hair dye formulas, the dye chemicals are pre-mixed
in hot water.
• The dye chemicals are dumped in a tank, and water which
has been already heated to 158°F(70°C) is pumped in.
• Other ingredients or solvents may also be added to the pre-
mix.
• The pre-mix is agitated for approximately 20 minutes

PROCESSPROCESS
MixingMixing
• The pre-mix is then added to a larger tank, containing the
other ingredients of the hair dye.
• In a small batch, the tanks used may hold about 1,600 lbs
(725 kg), and they are portable.
• A worker wheels the pre-mix tank to the second mix tank
and pours the ingredients in.
• For a very large batch, the tanks may hold 10 times as
much as the portable tanks, and in this case they are
connected by pipes.

PROCESSPROCESS
MixingMixing
• In a formula in which no pre-mixing is required, after checking and
weighing, the ingredients go directly to the mixing step.
• The ingredients are simply mixed in the tank until the proper
consistency is reached.
• If a heated pre-mix is used, the second mix solution must be allowed
to cool.
• The ingredients that follow the pre-mix may be additional solvents,
surfactants, and alkalizers.
• If the formula includes alcohol, it is no added until the mix reaches
40°C, so that it does not evaporate.
• Fragrances too are often added at the end of the mix.

PROCESSPROCESS
Packaging
• From the filling area, the bottles are taken to the packaging line.
• At the packaging line, the hair dye bottle is put in a box, together
with any other elements such as a bottle of developer or special
finishing shampoo, instruction sheet, and gloves and cap, or any
other tools provided for the consumer.
• After the package is complete, it is put in a shipping carton.
• The full cartons are then taken to the warehouse to await
distribution.

Evaluation
• Sensitization test (effect on skin & eye)
• Effect on hair (Half head test)

Test for developer
• pH (2 to 4)
• Assay for H2O2(max. 12 m/m)
– Assay % = VN1/N2M x 34.02
• Residue on evaporation (max. 0.2 m/v)
– % by mass = m/V x 100

Marketed Products
• Godrej,
• Garnier,
• L'Oreal,
• Lakme,
• Indica,

Hair dyes

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