Bleaching preparation

P.Vishal KumarB.Pharmacy 4th year

Section : BHT NO.256211881115

Mall reddy college of pharmacy

CONTENTS

Definitions Skin bleaching and whitening agents Formulations Manufacturing References

Definition:

Bleaching or skin lightening creams or ointments are widely used worldwide either to attempt to remove localised dark patches (e.g. melasma )or as a fashion trend aiming to reduce normal melanin in the skin.

An importing colour to the skin, the most important role is played by pigments, carotenes and melanins.

Melanins are responsible for racial difference. Skin lightening (bleaching) cosmetics and toiletries are used to lighten

the colour of darker skin. By definition, cosmetics are meant to improve the appearance of the

skin or enhance the attractiveness of users, not to alter the basic structure of the skin.

Skin bleaching/whitening agents:

Most commonly used skin bleaching agents are:1) Mercury compounds2) Hydroquinones3) Catechol and its derivatives4) Ascorbic acid and its derivatives5) Oxidizing agents6) Kojic acid7) Opaque covering agents

1)Mercury compounds:

Mercury compounds such as mercury chloride,red mercuric oxide and ammoniated mercury have been used skin bleaching effect.

Out of these ammoniated mercury was extensively used. But now, the mercury compounds are prohibited for use in cosmetics

and are no more used. mercury has been banned in most countries for use in skin whitening

(1976 in Europe, 1990 in the USA) because it accumulates on skin and it can have the opposite results in the long term.

2)Hydroquinones:

Hydroquinones is the Most favourite material which has been used. A concentration of 1.5-2.0% produces temporary lightening of the

skin. A concentration of 5% can produces redness and burning. The skin lightening effect of hydroquinones can be reversed by

exposure to sunlight.

3) Catechol and its derivatives

Some Catechols exhibited skin lightening effect . but these were less effective than hydroquinone. 4-isopropyl catechol is the most potent depigmenting agent. Concentration of 3% or more caused irritation and sensitizing reaction

and therefore, are not used in fairness prepartions.

4)Ascorbic acid and its derivatives

Ascorbic acid,through Very safe, do not seem to be very effective as pigmenting agents.

Used in skin bleaching cream containing hydroquinone as stabilizer(anti-oxidant).

Use of ascorbyl oleate has been reported in concentration of 3% and 5% in creams for bleaching freckles in human skin.

5)Oxidizing agents:

Hydrogen peroxide has been used in skin bleach cream. Zinc peroxide has been used in anhydrous ointments as bleaching

agents but its properties have not been proved.

6)Kojic acid:

It γ (Gama) pyrone compound. Commercialy it is produced by microbial fermentation using

aspergillus and pencillium spp. Both types of experiments i.e. in vivo and in vitro have shown that

kojic acid inhibits production of melanin. This inhibition has been shown to be due to chelation of copper, a

prosthetic group in tyrosinase. which is used in cosmetics for its excellent whitening effect.

7)Opaque covering agents:

Make-up products containg white or pale pigments such as titanium dioxide, zinc oxide, talc, kaolin, bismuth pigments can achieve remarkable temporary change in the colour of skin and hence these material have been mentioned here.

FORMULATIONS

SKIN LIGHTENING CREAMS

Hydroquinone is white crystalline material having melting point, 170-171˚c.

It is soluble in water in the ratio of 1:14 but freely soluble in alcohol and ether.

Its solutions become brown on exposure to air. Oxidation is much faster in alkaline solutions. Therefore, it is necessary to stabilized with anti-oxidants like

ascorbic acid and potassium metabisulphite.

Formula 1

Cetyl alcohol 10.0Mineral oil 3.5Sodium lauryl sulphate 1.5Hydroquinone 2.0Potassium metabisulphite 0.1Glycerin 6.0Ascorbic acid 0.5Water to make 100.0Perfume QSPreservatives QS

Formula 2

From the foregoing account it may be seen that only hydroquinone and pigments like titanium dioxide, zinc oxide, talc, etc…

Are safe and effective skin lighting agents. A formulation based on opaque covering agents (pigments) is given

below.

Formula 2 Stearic acid 2.0% Lanolin alcohol 5.0% Glyceryl monostearate 5.0% Oleyl alcohol 2.0% Triethanolamine 0.5% Propylene glycol 5.0% Titanium dioxide 7.0% Pigments 5.0% Water to make 100.0 Preservatives QS Perfume QS

5

SKIN BLEACH PREPARATION FORMULATION Mineral oil 5.0 Petroleum jelly 5.0 Polyethylene monosterate 6.0 Benzoyl peroxide 2.5 Potassium hydroxyquinolie sulphate 0.5 Glycerine 3.0 Water to make 100.0

METHOD OF PREPARATION

Heat the mineral oil, petroleum jelly and PEG monostearate to 75˚C. Heat the water also to75˚C. Add the hot water to oily phase with sterring. Con.. Sterring until cool. Add mixture of bezoyl peroxide, glycerine and potassium

hydroxiquinoline sulphate and mix well. This cream produces a slight burning effect on severly scarred tissue. However, this should not be taken as alarming. Burning sensation disappears rapidly after the intial application.

MANUFACTURE

Water phase

Oil phase

Higher fatty acids Higher fatty alcohols

emollients otherFat soluble materials

including preservatives

Purified water alkalis

Water soluble Preservatives

Heating to 70°c (for dissolving)

Stirring &

Mixing

dissolve

Heat

to

70°c

Other surfactantsChelating agents Perfumes Colouring agents Stirring

mixingDeairatio

n Cooling Mixing

Water phase

Controversy and negative health effects There is evidence to suggest that some types of skin-whitening

products use active ingredients (such as mercurous chloride) and hydroquinone which can be harmful.

Hydroquinone had been banned in Europe. However, it is now available again but only when prescribed by a

medical doctor. This is also the case in many other countries, where hydroquinone

can only be prescribed by a doctor for certain skin conditions. A test of common skin lightening creams available in Nigeria showed

that they caused mutations in bacteria and were possibly carcinogenic.

There is a growing market in skin lightening products that are toxin-free.

However, they are more costly due to their expensive ingredients. Japan and the Pacific are big markets for high quality skin lightening

products imported from Europe.

References

Cosmetics- formulations, manufacturing & quality control P.P. Sharma Poucher’s Perfumes, Cosmetics and Soaps by H. Butler, Chapman & HALL, London.

Guidance

Mrs. D. Nirmala Madam M.Pharm phD

THANK YOU