Formulation of Powders

FORMULATION OF POWDERS

Ingredients used in the formulation of powders are properly studied before selection. Their character, role and quality are taken into consideration, as they have effect on the finished product. The ingredients used should be of good quality.

Properties:

·                               They should not be hard in nature. If the materials are present in crystal form then they should not contain any sharp edges as it may damage the skin.

·                               They should have less solubility in water and mixtures of fat.

·                               They should be non-toxic in nature.

·                               They should be chemically stable, in order to prevent interaction with each other.

They should not cause irritation to the skin.

Ingredients And Examples

Covering Materials:          Titanium dioxide, zinc oxide, zinc stearate, kaolin, magnesium stearate and rice starch

Adhesive Materials:          Talc, magnesium and calcium salt of myristic acid, zinc stearate

Slip Materials:         Talc, magnesium stearate, aluminium hydrosilicate

Absorbent Materials:        Colloidal kaolin, starch, bentonite

Peach  Like  Finish:           Rice starch, maize starch, powdered silk

Materials       

Materials  Imparting:       Gualine, bismuth, oxychloride

Frosted-Look

Coloring Materials: Iron oxide, ultramarine, organic lakes and pigments

Perfumes:       Flowery fragrance or synthetic odour

Ingredients used in the formulation are classified based on their functions. They are as follows:

1.             Covering Materials:

These materials should be able to cover small imperfections, enlarged pores and minor blemishes of the skin. The covering power of powder is high, when its surface area is more..This can be achieved if the particles are in finely divided form. Medium in which these covering materials are dispersed plays an important role for imparting efficiency. Dry skin offers better covering power compared to moist skin. Examples:

(a)           Titanium Dioxide: It is considered as the best covering agent who is widely used in the formulation of face powders. It is inert in nature. It has 1.6 times more covering power on dry skin and 2.5 times more covering power on moist and greasy skin compared to zinc oxide; however it has less sunscreen property.

(b)           Zinc Oxide: It is also a good covering agent with good sunscreen property because zinc oxide has protective effect against ultraviolet rays. It consist of fine particles, which impart better covering power. But if the particle size is below 0.25 gm, then the covering power is reduced. And in case of moist and oily environment, of zinc oxide covering power is less i.e,. 37% compared to dry powders. Others materials which have less covering power are kaolin, zinc stearate, magnesium stearate and rice starch. They are used in combination to obtain products of different covering ability.

2.             Adhesive Materials:

Adhesive materials are essential as they are helpful in imparting adhesion i.e., it cling the powder materials not only to the surface of the skin but also to the powder puff. The adhesion of powder to the puff is necessary to take the powder out of the container in case of compact powders. Example:

Magnesium and zinc Stearate: Magnesium stearate is more preferred in the formulation of face powders in 3-10% and it has more adhesive property compared to zinc stearate .Whereas zinc stearate is used in the formulation of talcum powders.

Good quality of magnesium and zinc stearate is used because they provide excellent colour texture with minimum odour and also helps in provide velvety softness to the final product. These materials are water proof in nature. This helps in maintaining the complexion impact even in damp weather.

Other materials are lithium stearate, calcium stearate, talc, cetylalcohol (1-2%), stearyl alcohol, glyceryl monostearate, petrolatum, lanolin, and magnesium as well as calcium salts of myristic acid.

3.          Slip Materials:

Slip character helps in easy application and spreading of the powder on the skin, which in turn provide smoothness to the skin. Example:

(a)          Talc: it is a purified hydrated magnesium silicate.

Formula: H₂Mg₃ (SiO₃)₄ or Mg₃Si₄O₁₀ (OH) ₂

It is widely used in the formulation of face powders. It helps in imparting slip character along with softness. It is neutral and cannot absorb water.

(b)          Aluminium hydrosilicate:

·                               It is considered as the basic material for the formulation of powders.

·                               It is smooth, fatty and non-toxic in nature.

·                               It is prepared by treating acid and then washing with water. Finally drying is carried out.

·                               It also produces cooling effect.

·                               It also absorbs fatty secretions and water (in small quantity).

Other materials are zinc stearate, magnesium stearate, zinc undecanate and magnesium undecanate.

4.           Absorbent Materials:

These materials should be able to eliminate shine from the skin surface by absorbing the secretion of the skin i.e., sebum and perspiration (sweat).

Examples:

(a)          Colloidal Kaolin:

·                               It is fine, white colour powder, which is soft in nature.

·                               It is non-toxic and inert in nature.

·                               It does not cause irritation to the skin.

·                               It absorbs aqueous and fatty substances which show that it has good absorbing capacity.

·                               It has good covering power along with less slip property.

(b)            Bentonite or Aluminium Silicate:

·                               It is fine, whitish-grey powder.

·                               It has good swelling power i.e., can swells up to 12 times of its own volume.

·                               It is not widely used in cosmetics.

(c)          Magnesium Carbonate:

·                               It has good absorbing capacity for water and fatty substances.

·                               It is less alkaline in nature.

·                               Covering power and adhesive property are more, which all the perfume oil to be added first in magnesium carbonate and then mixed with other materials.

(d)           Calcium Carbonate: It is fine, white coloured powder, which is soft in nature. It has properties similar to that of magnesium carbonate. It is less preferred, as it undergoes alkaline reaction pith skin. Other materials are rice, wheat, corn, potato etc., which have both absorbing and swelling properties. These materials impart sticky character and are non-toxic in nature.

5.             Peach-Like Finish Materials:

These materials help in imparting peach-like finish appearance, which provide bloom to the skin. Examples:

(a)           Rice Starch: Other starches are also used like maize starch. They are used after drying (i.e., few hours) in order to get better effect.

(b)          Silica: it is finely divided material which imparts fluffy appearance to the skin.

(c)          Powdered Silk: This material is obtained from silk proteins. These proteins are subjected to the process of partial hydrolysis which produces hydrolysate. This hydrolysate is grounded to obtain fine powder. They are used in 30% quantity.

6.           Materials Imparting Frosted-Look:

This material is capable of producing translucent lustre and shiny look to the skin. It also imparts pearlescence.

Example: Guanine (It is not widely used because it is expensive), bismuth oxychloride, mica, aluminium, bronze.

7.          Colouring Materials:

These materials are mainly used in the formulation of face powders and compacts in order I impart colour.

Examples:

(a)           Iron Oxide: It is an inorganic pigment, which is used for imparting yellow, red and brown colour.

(b)          Ultramarine: This material is used to impart green and blue colour.

(c)          Organic Lakes and Pigments: These materials are capable of producing better brilliance the skin. They should not bleed (i.e., loss of colour) in oil and water solvents.

8.          Perfumes:

Flowery fragrance or synthetic odour are used in the formulation of powders. Perfumes should be compatible with the other ingredients in the formulation. Otherwise, the perfume character will change.