INTRODUCTION
Link for video demonstration of this topic 👇
https://youtu.be/QHwms3VDRxc (Part 1)
https://youtu.be/v6Oug9RqMKA (Part 2)
Formulation-
https://youtu.be/Wp7NV46Y8Os (Part 1)
https://youtu.be/t5-aFS4AV78 (Part 2)
Preparation-
https://youtu.be/RYPuVHlA-hY
Evaluation-
https://youtu.be/TXwpWMMwRhI
A viscous cosmetic preparation with synthetic detergent used for washing hair is called shampoo.
Its principle function is to clean the scalp such that it should become free from sebum and foreign substances.
IDEAL PROPERTIES
Ideal properties are:
• It should have optimum viscosity such that it facilitates ease during application.
• It should have good spreading properties.
• It should produce sufficient lather after application.
• It should be able to remove waste material such as debris, soil, sebum, dead cells, salts (due to sweat) etc., from the scalp.
• It should not form any kind of film on scalp.
• It should rinse out completely after washing.
• It should produce lather with both hot and cold water.
• It should facilitate ease of combing after shampooing.
• After drying, the hair should not give rough appearance.
• It should provide lustre to the hair.
• It should produce good odour both before and after shampooing.
• It should not produce any kind of irritation or itching to the scalp.
• It should not support any microbial growth.
• It should be stable and have a half life of about 2 to 3 years.
• It should be economical.
TYPES OF SHAMPOOS
1. Clear liquid shampoos
2. Liquid cream shampoos
3. Cream shampoos
4. Gel shampoos
5. Powder shampoos
6. Aerosol shampoos (Foam type)
7. Special shampoos
1. Clear Liquid Shampoos: These are clear liquid preparations that are most widely used. They are usually made by using detergent of low cloud point.
2. Liquid Cream Shampoos: These are called as lotion shampoos which are modification of clear liquid shampoos. Addition of opacifier such as glycerylmonostearate, glycol stearate etc., to the clear liquid shampoo yields liquid cream shampoo.
3. Cream Shampoos: These shampoos have a paste like consistency and are packed in a collapsible tube. The paste consistency is developed by addition of alkyl sulphates, also Cetyl alcohol is added, which serves as a builder.
5. Powder Shampoos: It is available in the form of dry powder, initially it was prepared from dry soaps, but nowadays dry synthetic detergents are used for their preparation. Powder shampoo is prepared where addition of water or other solvent reduces the activity of the components, especially in case of medicated shampoo. Nowadays, these shampoos are not used due to the difficulty experienced in their application.
6. Aerosol Shampoos: They are called aerosol shampoos because they are packed in aerosol containers .Their formulation, preparation and packing is complicated as an additional propellant is included. The propellant added must be compatible and should not reduce the activity of shampooing ingredients. The container opening is provided with a valve. Shampoo comes out as foam when the valve is pressed. Hence also called as foam type shampoo.
7. Special Shampoos:
(a) Medicated shampoo: These shampoos contain medicinal agents. These agents treat the disorders of the scalp or hair. Examples of medicated shampoos are: Anti-lice shampoo, Anti-dandruff shampoo, Anti-baldness shampoo etc,.
The medicinal agent added should not irritate the sebaceous glands. It should not sensitize the scalp. The degree of itching and scaling should also be reduced. Among all, anti-dandruff type of medicated shampoo is most widely used.
(b) Conditioner Shampoos: These shampoos serve for hair conditioning. Initially they clean the hair (and scalp) and keep them in smooth and lustrous condition.
Most of the conditioners are made from Quaternary ammonium compounds. These compounds have the property of reducing electric charges between the hair, as a result hair become lustrous easily manageable. These compounds can also exhibit a bactericidal effect.
FORMULATION OF SHAMPOO
Surfactants: The main use of surfactant is to cleanse and to produce foam. They are generally categorized into four types.
They are:
(a) Anionic Surfactants
(b) Non-ionic surfactants
(c) Cationic Surfactants
(d) Amphoteric Surfactants
(a) Anionic Surfactants: These surfactants have good foaming property, hence they are used as principle surfactant. They are considered as main ingredient of shampoo formulation.
Examples of Anionic Surfactants: Alkyl sulphates (Lauryl Sulphate), α- olefin Sulphate (sulphosuccinates) etc.
(b) Non-ionic Surfactant: These are considered as secondary surfactants. They are not used to produce foam but used as foam boosters, viscosity inducers, emulsion stabilizers and opacifiers. This is because they have less foaming power. Even though they have good cleaning property, they are not used as principle surfactant. Examples of Non-ionic surfactants: Poly-alkoxylated Derivatives, Fatty Acid alkanolamides (Lauric Monoethanolamide).
(c) Cationic Surfactants: Surfactants that contains positive charge are called as cationic surfactants. They are used as both principle and secondary surfactants. These surfactants are used in low concentrations because they are toxic to eye. Hence, they are considered as secondary surfactants. Apart from the above toxic effect, they also have good foaming and partly cleaning properties. Hence, they are also used as principle surfactants in conditioner shampoos. Examples of Cationic Surfactants: Alkylamines, Ethoxylated amines.
(d) Amphoteric Surfactants: The surfactants which possess both cationic and anionic charges with respect to acidic and basic media are called as amphoteric solvents. They form zwitterions when the pH of media is neutral.These agents produces a mild action and show compatibility with surfactants . They posses excellent hair conditioning property and hence used as secondary surfactants. Examples of Amphoteric Surfactants: Dialkyl Ethylene Diamines, N-alkyl Amino Acids.
Foam Boosters: They form rich lather i.e. foam which is stabilized or strengthened by using a substance called foam boosters. They make the foam dense and it to remain for long duration. Usually they are added in quantity of about 2 to 5%.
Fatty acids and fatty alcohols when added in a range of 0.25 to 0.50% concentrations, they also act as foam boosters.
Examples of foam boosters: Monoethanolamides, lauramides DEA etc.
Germicide and Anti-dandruff Agents: Germicides are the agents which prevent the growth of micro-organism on the scalp whereas anti-dandruff agents are used to eliminate dandruff from the scalp.
Examples of Germicides are:
• Quaternary ammonium compounds: Benzalkonium Chloride, Cetrimide etc.
Examples of Anti-dandruff Agents are:
• Selenium Sulphide
• Cadmium Sulphide
Conditioning Agents: These agents improve the condition of hair. These agents have the property of reducing, electric charges the hair, as a result, hair become lustrous and hence easily manageable. These agents also exhibit a bactericidal effect. They make the hair silky and shiny.
Examples of conditioning agents: lanolin, oils, herbal extracts, egg, amino acids etc. of which amino acid gives good conditioning effect.
Pearlescent agent: These agents are usually added as adjuvants to the conditioning agents. They improve the conditioning property. Addition of these agents also imparts brightness to hair. They make the preparation opaque; hence they are also called as opacifying agents.
Example of pearlescent agents are alkanolamides and coumarins like 4-methyl-7-diethyl amino coumarin, 4-methyl-5, 7-dihydrocoumarin etc.
Sequestrants: These are complex forming agents. They form complex with metal ions like calcium and magnesium. Surfactant are liable to form complex with the metals present in water i.e., calcium and magnesium. Hence addition of Sequestrants prevents complex formation between metal and surfactant. The Sequestrant itself forms complex with the metal ions. Thus, it prevents the formation of film on the scalp i.e., the film formed by surfactant and metal ions. The commonly used Sequestrants are EDTA, citric acid etc,.
Thickening agent: These agents are usually added to make the preparation thick i.e. viscous. Such viscous preparation facilitates ease of handling. Also, they prevent wastage during application. Already the addition of various agents, such as surfactants, foam boosters etc make the preparation viscous even though thickening agent is added.
Example of commonly used thickening agent are methyl cellulose, alginates polyvinyl alcohol, polyethylene glycol etc.
Perfumes: Addition of these agents imparts good fragrance to the shampoo. It also neutralizes the undesirable odour of other ingredients of formulation especially surfactants. Nowadays it has become an important factor for consumer satisfaction. The selected perfumes must be such that they should retain good smell for fixed period of time even after shampooing. The added perfumes should not affect the solubility and stability of the preparation. They are usually obtained from natural sources such as flowers, fruits, herbs etc.
Preservatives: These agents have the ability to prevent the growth of micro-organisms. They are usually added to maintain the stability of the preparation for a desired period of time. Shampoo is a wet preparation that provides a media for various micro organisms hence addition of preservative is essential. Preservative used should not cause any irritation to the scalp.
Example of commonly preservatives are para-hydroxybenzoic acid and phenyl mercuric nitrate.
Colouring agents: Addition of colour gives pleasant appearance to the preparation. Various FD & C dyes are used for colouring the preparation. The added colour must be water soluble and it should not impart any colour to hair or scalp.
PREPARATION OF SHAMPOO
Liquid Shampoo Preparation
• Initially the detergent is converted into a solution form or a detergent solution directly obtained from the manufacturer.
• Take about half of the detergent solution into a separate container. To it, add the total amount of secondary surfactant i.e., alkanolamide.
• Dissolve the alkanolamide along with stirring. Sometimes, gentle heat is also applied.
• To the remaining half of the detergent solution add suitable amount of perfuming agent and dissolve it.
• The perfume solution is then added to the alkanolamide solution.
• Colour and preservatives are dissolved separately in sufficient volume of water and then added to the main solution.
• The whole, solution is mixed well by gentle stirring. Excessive stirring may lead to bubble formation.
• Final volume of the preparation is usually adjusted by the addition of clear sterile water. This gives clear liquid shampoo.
• However, when the preparation contains lauryl alcohol ether sulphate. It is required to adjust the viscosity of the shampoo.
• Viscosity adjustment is done by using an electrolyte solution. Usually, a solution of sodium chloride is added subsequently with constant stirring.
Cream Shampoo Preparation
• Initially, a solution of detergent and water are heated to about 80°C.
• The wax is heated separately in a container at 80°C which facilitates the melting of wax.
• Both the solutions are kept at 80°C and mixed uniform mixing by constant and gentle stirring.
• The solution is allowed to cool to about 40- 45°C. After which the remaining ingredients, such as additives, colours, perfume and preservatives are added. The stirring is continued.
• Finally, under warm conditions, the mixture is transferred into a suitable container and packed.
Gel Shampoo Preparation
The method involved in the preparation of gel shampoo is similar to that of clear liquid shampoo. After preparation, the liquid shampoo is usually treated with a suitable thickening or gelling agent such as hydroxy propyl methyl cellulose, this gives a gel like consistency. Addition of appropriate amount of anionic and amphoteric surfactants also leads to the formation of gels.
Aerosol Shampoo Preparation
This type of shampoo is initially prepared by using (earlier discussed) general method. The prepared shampoo is then incorporated with a suitable propellant. The whole mixture is packed in an aerosol container. The propellant creates a pressure within the container due to which spraying action is achieved and the product (shampoo) is sprayed in the form of foam. Here packing plays an important role and the propellant used should not react with the shampoo.
Powder Shampoo Preparation
Powder shampoo is prepared by simple blending. Here, all the ingredients are taken in a state. They are powdered to suitable degree of fineness. The powdered ingredients are blended by using a suitable blender. Two separate solutions of perfume and colour are prepared by using alcohol or water as solvents. The prepared solutions are then sprayed onto the blended mixture. The wet mixture is dried and packed. Otherwise, the ingredients are internally soaked into the solutions of colour and perfume. Wet mass is dried and then subjected to blending.
EVALUATION OF SHAMPOO
Shampoos are evaluated for the following aspects.
(I) Evaluation of Safety
(II) Evaluation of Antimicrobial Property.
(I) Evaluation of Safety: Safety is an important aspect which must first and foremost parameter of evaluation. As stated earlier the shampoos are made from synthetic detergents, which are liable to irritate skin, scalp and eye. Hence, it becomes essential to evaluate the safety of a shampoo.
(a) Skin Toxicity Test: The steps involved in this test are as follows:
- A set of six albino rabbits are selected. They should weigh about 2 kgs.
- On the skin of each rabbit, a round patch is made by removing hair.
- Dilute preparation (8-10%) of shampoo is usually applied onto the patches of a rabbits.
- The shampoo is allowed to react for a period of 3-4 hours.
- After that it is removed completely from the skin.
- After efficient washing, the skin is examined for any adverse reactions such as erythema, edema etc.
- Based on the results obtained the shampoo is considered as either safe or toxic.
- Usually, there might be chances of adverse reactions because the shampoo was kept in contact for 4 hours. But usual practice of shampooing in human being is for 10-15 minutes.
- Alternatively, the skin test is also performed on human being.
(b) Eye Toxicity Test: The steps involved in this test are as follows:
- A set of six adult albino rabbits are selected. They must weigh about 2 kgs.
- One eye of each rabbit is considered as test eye and another as control eye.
- To each of the six test eyes of six rabbits, the product (shampoo) is applied.
- Washing is done after 20 seconds with 200 ml of tap water.
- Test eyes are rewashed after 5 minutes and then after 24 hours.
- The control eye are also washed on first day and then after 24 hours.
- The test eyes are observed at 1, 24, 48 and 72 hours respectively.
- They are also examined on 7th and 14th day.
- The product is said to be toxic, if there is a development of iris and corneal lesions which remains for more than 7 days.
(II) Evaluation of Antimicrobial Activity: Shampoos are liquid or viscous preparations, they are liable to microbial growth. Hence, preservative is usually added to prevent midi growth .The added preservative should have following properties.
• It should be non toxic.
• It should be compatible with other ingredients.
• It should be effective at low concentration,
• It should be effective against wide variety of microorganism.
Procedure (Challenge Study):
• Initially an appropriate strain of microorganism is selected and is considered as test organism. Usually the species of Pseudomonas are selected i.e., P aeruginosa, P. Putida etc.
• A culture of any one of the above test organisms is prepared.
• The product (shampoo) is then inoculated repeatedly in the culture medium and the studies are carried out for a period of 10 to 12 weeks.
• The inoculums usually contain 5 lakhs to1 crore micro organisms/ gm of product.
• Along with the test, control samples are also prepared and reserved for reference.
• Usually two types of control samples are prepared i.e., one sample with preservative and another without preservative.
• The test comes to a conclusion only when it has been proven that the product has not supported the microbial growth.
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