cosmetic / lipstick /waxes/formation of lipstick

The Solid Components/waxes: the solid components are responsible for the final

Structure of the product by solidifying the liquid matrix. The materials required for attaining a

Reasonable body, hardness, melting point and shrinkage necessary for the easy release of theMould are together referred to as natural waxes.The solid components of the formulation are mostly natural waxes which may be classified as

Follows:

The hydrocarbon waxes: Example: White bees wax

(a) The mineral waxes: Example: Ozokerite, ceresine

(b) Hard waxes: Example: Carnauba wax, candelilla wax, hard paraffin etc.

Micro crystalline waxes

•Hydrocarbon Waxes : White Bees wax: It is a so known as the common wax and forms the oily base in the

Formulation of lipsticks.

Source: It is naturally obtained from honey combs of the honey bee Apis mellifera.

Melting Point: the ranges between 62 – 65°C.

Concentration: It is used in concentrations of about 3-10% of the total formulation.

Available Forms: It is available in the form of blocks, pills, slabs and cakes. The Commercially available bleached form is widely used.

Uses:

1. It forms an important base and is extensively used for entrapping castor oil.

2. It has good plastic property and can be readily deformed when it is warmed.

3. It is used as a traditional stiffening agent for lipsticks.

4. It forms a good base in the formulation of moulded products. Advantages:

1. It is compatible with vegetable minerals and animal waxes.

2. It can be moulded into required form.

Disadvantage: When it is used at a concentration of more than 20%, it forms a dull film on The surface of the lips. It is usually mixed along with other waxes such as Ozokerite wax, Carnauba wax and candelilla wax.

Mineral Waxes: They are not popular and have been replaced by the microcrystallineWaxes but still used with the same names. They are:

(i) Ozokerite Wax:

Source: It is a type of amorphous hydrocarbon obtained naturally, from bituminous products.

Melting Points: It is available in various grades with melting point ranging between 56°C -82°C.

Uses:

1. It is used in order to increase the Melting point of the base.

2. It is also efficient in promoting the formulation of a fine crystalline wax gel and thus Ensures the maximum retention of the Oil matrix.

3. can be easily transformed into required shapes.

Advantage: It is easily available in various grades.

Disadvantage: It may be subjected to adulteration.

(ii) Ceresine Wax:

Source: It is also obtained naturally from the bituminous products like the Ozokerite wax.

Melting Point: The melting point range is between 60-75°C.

Uses:

1. It is used as stiffening agents to provide firmness to the finished product.

2. It is used to increase melting point of the base.

© The Hard Waxes: These waxes are mainly responsible for the shape and the hardness of

The lipsticks. They include the following waxes,

(i) Candelilla Wax:

Source: It is obtained from Euphorbiaceae plants such a Euphorbia cerifera and Euphorbia

Antisyphilitica. The extraction involves the immersing of the plant in boiling water containing Sulfuric acid and later skimming off the wax that rises to the surface. Melting Point Its melting point ranges between 65°C 75°C.

Uses: It is used to increase the hardness and melting point of the product either alone or in Combination with carnauba wax.

(ii) Carnauba Wax:

Source: It is obtained as exudates from the pores of the leaves of the Brazilian wax palm tree

Copernicia prunifera. The extraction involves cutting, drying and heating of the leaves.

Melting Point: Its melting point ranges between 81 to 90°C.

Available Forms: It is available in three colors yellow, gray and brown. It is available in hard Forms and soft forms.

Uses-

1. It is used to provide rigidity to the stick.

2. It is used in modest proportion in order to ensure high melting points.

3. It helps in moulding by shrinking the stick away from the surface of the mould in order to

Aid easy removal.

Disadvantage: It is not miscible with the other waxes and remain as a separate solid phase Due to its high melting point.

(i) Carnauba Wax

Source: It may be present as a purified blend of several solid Hydrocarbon bases that are Obtained from petroleum.

Melting Point: Its melting point ranges between 55°C – 65°C.

Uses:

1. It is occasionally used in minor quantities to improve the gloss of the finished products.

2. Imparts rigidity to the product.

Disadvantage: It has limited solubility in the castor oil and hence doesn’t dissolve and may Provide a greasy look.

(b) Microcrystalline Waxes: They are the hydrocarbons containing a long carbon chain.

Melting Point: They have wide melting points ranging between 60°C to 120°C.

Uses:

They help in maintaining the crystal structure of the lipstick and hence may prevent the

Sweating.

Disadvantage: They possess low solubility in the castor oil.

3. The Liquid Components: The liquid components are mostly constituted by the oils such As mineral oil, vegetable oil, castor oil, alcohol etc. The properties of the oils should be as

Follows:

(i) It should possess good dissolution properties in order to dissolve all the bromo acids.

(ii) It should possess an optimum viscosity range.

(iii) It should be colourless, odourless and tasteless.

(iv) It should be non-toxic and non-irritating.

(v) It should be easily compatible and stable.

The most commonly used liquid components may be as follows:

(a) Mineral Oils:

(i) They consist of a blend of hydrocarbons obtained from petroleum source.

(ii) They may be avail ale as either light mineral oils or heavy mineral oils.

(iii) They are mostly used in order to impart gloss to the product rather than their solvent

Property.

(iv) They are used in concentrations of less than 5% and are not rancid.

(b) Vegetable Oils: The vegetable oils used may be sesame oil and olive oil. The vegetable

Oils provides low solubility towards staining dyes and hence less commonly used.

© Castor Oil: It is obtained from the seeds of the castor plant, Ricinus communis. It forms a Most valuable lipstick base. It may be used in concentration of 40 – 50% of the total

Formulation. It has high viscosity and good dissolving power. It possesses stability towards

Oxidation. It is widely compatible with other ingredients. The high viscosity may avoid Smearing off of the lipsticks.

(c) Butyl Stearates: They are useful for the dispersion of colour though they possess less

Solubility. They can readily wet the colouring pigments. They are odourless and free from Rancidity.

 propylene Glycol: It is non-toxic and possesses a sweet taste. It has good wetting Property towards high colouring stains. It is always used in combination with other Monoesters of propylene glycol.

(f) Water: It is not used as a solvent but may be used in minor quantities in order to dissolve The colour.

(g) Silicone Fluid: It is mostly used to aid in mould release and prevent the rub-out of the Wax. It is used in minor quantities.

(h) Isopropyl Maleate (IPM): It is used in concentration of 2.3% to increase lip gloss. It acts As a co-solvent along with mineral oil and helps in increasing lip gloss.

4. The Softening Agents: They are used to increase the spread ability by softening the Lipstick. The most commonly used softening agents include.

(a) Anhydrous Lanolin: It is also known as wool fat or woolwax. It is used at low Concentration of about 0.25% in order to impart gloss, softness, emolliency and protection to The lips. The melting point ranges between 36 – 42°C.

(b) Lanolin: It is also referred to as hydrous wool fat. It is used in minor quantities in order To improve the covering properties of the film. It contains 25-30% of water and may result in Sticky and greasy products. It aids in the dispersion of colored pigments.

© Lanolin Derivatives: They include ethers, esters and lanolin oils. They are almost none Drying and thus provide a non-greasy look to the film. They are also used as blending agents Or plasticizers.

(c) Cocoa Butter: It was used in the past due to its good emollient property. The usage has Been stopped due to rancidity and surface crystallization. It provides oily look on the lips and Hence imparts good gloss.

 Petrolatum: It is a hydrocarbon obtained from petroleum. It is odourless and tasteless. It Is added mainly to enhance the gloss.

(f) Lecithin: It is used in minor quantities to impart smoothness and emollient effect. It Increases the ease of application.

5. Colouring Agents: Colour may be imparted to the lips either by staining the lip with a dye Stuff colour or by covering the lips with coloring layers. The colours used in the formulation Of lipsticks are of two types:

(a) Soluble Colours: They are dye stuff agents which are easily soluble in oil, water and Alcohol.

(b) Insoluble Colours: They are organic or inorganic pigments which are insoluble. Properties of Colouring Agents: They should impart good opacity to the lips by imparting good colour. They should he easily and uniformly miscible with the oils used. The colours must he certified with the F, D and C grade. They should possess very low content of impurities such as arsenic, lead etc,. The commonly used colourants for lipsticks:

(i) Carmine: It was extensively used in the past and is obtained as carminic acid from the Cochineal insects by extracting the insects with ammonia. The carminic acid obtained is Precipitated with alum and is dried and used.

(ii) Dye Stuff Stains: They include eosin dyes and provide a long lasting effect on the lips by Retaining the color on the lip cells. They are:

(a) Eosin Dye: It is used to impart orange red colour to the lips.

(b) Acid Eosin Dye: It has orange colour and may change to intense red colour at acidic pH Of 4. But they may to toxic effects such as allergic reactions or cheilitis and hence used alone With bromo acids.

(iii) Pigmented Stains: They form dispersion in the solvent base. They may be either organic Or inorganic. They are used in combination with metallic lakes in order to improve the Intensity of the colour

(iv) Lakes: They are potential pigments of many of the D and C colours. They may be Adsorbed on the aluminium hydroxides, barium oxides, calcium oxides etc,.

Example: Aluminium lakes, barium or calcium lakes, strontium lakes. They are used at Concentrations of about 8-10%.

6. Pearlescent Pigments: They are used to impart nacreous or a pearl like appearance to the Product when applied on the lips. The natural pearlescent pigments may be guanine crystals Obtained from fish scales. Bismuth oxychloride in 70 % castor oil may also provide a lustrous Look.

7. Opacifying Agent: It is used for opacifying or whitening of lipsticks. It can also alter the Basic shade of the pigment. Various shades can he obtained by, varying the proportions.

Example: Titanium Dioxide.

8. Perfumeries: Light floral fragrances can be used in lipsticks. They include rose oil, Cinnamon oil, lavender oil etc. The fruity flavours that cover fatty odour of the oily waxes May also be used. They should be tasteless, non-irritating and compatible.

9. Miscellaneous Agents: They include the following:

(a) Preservatives: They are used to increase life period of the product by reducing the Microbial growth. Though they are anhydrous preparations, preservatives such as methyl Paraben and propyl paraben may be commonly used. The concentration of the preservative Should not exceed 0.1%.

(b) Antioxidants: The ingredients used in the formulation may be susceptible to oxidation. This may result in the degradation of the product. Thus, antioxidants are added in order to Prevent oxidation of the ingredients. The commonly used antioxidants are butylated hydroxyl Anisole (BHA), butylated hydroxyl toluene (BHT), tocopherol, propyl gallate, butylated Hydroxyl quinines etc. © Flavouring Agents: They are included in order to impart good flavor to the product. They May include the spearmint oil, cinnamon oil etc. Along with the flavouring agents, sodium Saccharin and the ammonium glycyrrhizate may also be used in order to improve the taste.

Preparation of lipsticks:

Successful preparation of lipstick shades depend upon the adequate dispersion of the lake

Colours in the lipstick mass. It is advisable to prepare the dispersion of lake colours in castorOil. Dispersions are generally prepared by milling about 25% concentrations of lakes in castor Oil.

Method of Preparation:

If a solvent is used for the dissolution of bromo acid, the solution is first prepared and Set aside until required. If commercial colour pastes are not being used, then lake colours are first dispersed By mixing with suitable quantity of castor oil. The colour paste obtained is passed through a triple roller mill until it becomes Smooth and free from agglomerates and gritty particles. The colour mixture is then mixed with the bromo acid mixture. All the ingredients of the base are identified and arranged in the increasing order of Their melting points. This mixture is remilled until it is perfectly smooth. Preservatives and anti-oxidant are dissolved in remaining oil and are added to the Mixture. Finally, the perfume is added and the mass is stirred thoroughly, but gently to avoid Entrapment of air. Automatic ejection mould is preferred for the large scale production. The mould is lubricated with liquid paraffin or isopropyl myristate before pouring the Mass into the mould.It is important to prevent settling down of the coloring mass when the moulds are Chilled. Lubrication facilitates easy removal of sticks.

Evaluation of Lipsticks

The evaluation studies are important in order to determine the efficiency, stability and the Consistency of the finished product. The evaluation tests for the lipsticks are as follows:

1. Melting Point Determination Test: The determination of melting point is done in order to Determine the storage characteristics of the product. The inciting point of lipstick base should Be between 60 to 65°C in order to avoid the sensation of friction or dryness during Application. The method of determination is known as capillary tube method:

(a) In this method, about 50 mg of lipstick is taken and is inserted into a glass capillary Tube open at both ends.

(b) The capillary tube is ice cooled for about hrs and then placed in a beaker containing Hot water and a magnetic stirrer. © The temperature at which material starts moving through the capillary is said to be The melting point temperature.

(c) Another important parameter is the droop point which determines the temperature at Which the product starts oozing out the oil and becomes flattened out.

 The melting point should be higher than the droop point which determines the safe Handling and storage of finished product.

2. Breaking Load Point Test: This test is done in order to determine the strength and Hardness of the lipstick. In this method, the lipstick is placed hori7ental position I inch from The base and weights with increasing loads are attached to it. The weight at which the lipstick Starts breaking, known as the breaking load point. The test shall be carried out in specific Condition and at about 25 ° C temperatures.

3. Determination of thixotropic character: This is a test for determining the uniformity in Viscosity of base. The instrument used for the determination of thixotropic character is known As the penetrometer.

4. Microbiological tests: The test is carried out in order to determine the extent of Contamination either from the raw materials or mould. The test involves the plating of known Mass of sample on two different culture media for the growth of microorganism and Incubating them for a specific period of time. The extent of contamination can be estimated By counting the number of colonies.

5. Test for rancidity: the oxidation of oil such as castor oil and many other ingredients may Result in bad odour and taste and also result in a sticky product. The test for rancidity can be Done by using hydrogen peroxide and determining its peroxide number.

6. Test for the Application Force: This is a test to determine the force to be applied during Application. In this method, two lipsticks are cut to obtain flat surfaces which are placed one Above other. A smooth paper is placed between them which is attached to a dynamometer to Determine force required to pull the paper indicates the force application.

7. Storage Stability: This test is done in order to determine the stability of product during Storage.

8. Stability to Oxidation: The oxidation characteristics of the finished product are Determined in order to check the stability of the product to oxidation. The extent of oxidation Can be determined by peroxide number of product after exposure or substance to oxygen for a Specific period of time.

9. Determination of Surface Characteristics: the study of surface property of the product is Carried out in order to check the formation crystal on the surface or the contamination by Microorganism or formation of wrinkles and the exudation of liquid.

10. Determination of Colour dispersion: the test is done in order to determine the uniform Dispersion of color particle. The size of the particle is determined by the microscopic studies And it should not be more than 50µ.