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. 4. Powders producing Definition area per unit weight. This Powders are considered as one of the important products helps in proper dispersion of skin care preparations. They are used widely by both of powder, which covers men and women for face and body care. Various types of the large surface area of the powders are body powder, face powders, compacts body. medicated powders (which are used for prickly heat purposes and preventing microbial growth on the surface of the skin), deodorant powders and foot powders for treatment purposes). Powders have different physical properties when compared to the liquid preparations. They have very fine particle size, which helps in large surface Characteristics:  It should possess good covering Power in order to hide blemishes present on the skin.  Adhesion property should be good, so that it should not blow-off easily from the skin.  It should remain on the skin for longer period of time to avoid re-powdering.  It should be able to impart matt or peach like appearance to the skin.  It should remove the shine present on the skin as well as around the nose.  It should possess good absorbent property.  It should be able to produce, slip property to the skin for easy spreading by puff without producing any blotches (irregular marks).  It should be able to produce transparency effect. 4.1 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 1. Covering Materials Examples Titanium dioxide, zinc oxide, zinc stearate, kaolin, magnesium 2. Adhesive Materials 3. Slip Materials 4. Absorbent Materials 5. Peach Like Finish stearate and rice starch Talc, magnesium and calcium salt of myristic acid, zinc stearate Talc, magnesium stearate, aluminium hydrosilicate Colloidal kaolin, starch, bentonite Rice starch, maize starch, powdered silk Materials 6. Materials Imparting Gualine, bismuth, oxychloride Frosted-Look 7. Coloring Materials 8. Perfumes Iron oxide, ultramarine, organic lakes and pigments 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. 4.2 Classification of powders Three different types of powder products are used in cosmetics, which are as follows: 1. Face powders 2. Compacts 3. Body powders / Talcum powders / Dusting powders. 1. Face Powders: These powders can complement the skin colour by providing velvety finish to it. Properties:  It should impart smooth finish to the skin.  It should mask minor imperfections (which are visible) on the skin.  It should eliminate shine present on the skin due to moisture or grease.  It should have long lasting property to avoid frequent application.  It should be resistant to the secretions of the skin i.e., sebaceous and perspiration.  It should serve as a vehicle to perfumes so that the particles of perfumes may spread easily. A single substance is unable to impart all the characters i.e., covering power. Slip character absorbent capacity, adhesive property. Hence, mixture of substances is used in the formulation of powders to impart desired properties to the skin. Depending on the type of skin to be powdered, the face powders are classified into 3 types. Formula Talc (slip character) Kaolin (covering materials) Calcium carbonate (absorbent) zinc oxide (covering materials) zinc stearate (slip character) Magnesium carbonate (absorbent) Color Perfume (odour) Quantity for 100 g 63 g 20 g 5g 5g 5g 1g 0.5 g 0.5 g They are light type, medium type and heavy type. (i) Light Type: These types of powders are applied on dry skin. They have low covering power since the dry skin does not secrete any oils. Large amount of talc will be present in the formulation of powders. Method: It is a dry mixing method. Perfume is added to some part of calcium carbonate, which is absorbent and mixed thoroughly. This preparation is kept aside for some time. This is mixture A. Color is add added to some part-of talc and mixed thoroughly. This is mixture B. Then kaolin, zinc oxide, zinc stearate, magnesium carbonate and remaining part of calcium carbonate and talc are added to mixture B and mixed properly. Mixture A is added to the above mixture and mixing is carried out. Finally, the preparation is sieved by using either a silk mesh or nylon cloth. (ii) Medium type: Type of powders is applied on the normal or moderate oily skins. These skins are shiny in nature due to the sebaceous secretions or perspiration (sweat). They have good covering power compared to light type. They contain less quantity of talc along with slightly more quantity of zinc oxide (The less quantity of talc is balanced by zinc oxide). Formula Talc (slip character) Kaolin (covering materials) Calcium carbonate (absorbent) zinc oxide (covering materials) zinc stearate (slip character) Magnesium carbonate (absorbent) Color Perfume (odour) Quantity for 100 g 39.7 g 39.5 g 5 g 7 g 7 g 1g 0.2 g 0.6 g Method The method is same as that of light type of face powders. (iii) Heavy type: These types of powders are applied on extremely oily skins, which have more shine due to secretions. They have high covering power, in order to cover the shine of the skin. They, contain less quantity of talc and more quantity of zinc oxide. Formula magnesium stearate (covering materials) Kaolin (covering materials) zinc oxide (covering materials) Calcium carbonate (absorbent) Talc (slip character) Quantity for 100 g 5g 20 g 15 g 39 g 20 g 2. Compacts: loose powder or dry powders are compressed in the form of cake along with binder by compaction process; in order to form compact Powders. Compact are applied on the face with help of powder puff. The pressure used in compaction process is an important factor in the formulation of compacts. As low pressure may form cake which break easily during use and high pressure form very hard cake which will not adhere to the puff easily. The average particle in compact powders is looser compared tri loose powders, due to compaction. Ingredients: The composition of compact powder is similar to face powder but binding agents e incorporated, in order to increase adhesion property. Binders 1.Dry binders (requires increased pressure Examples zinc stearate, magnesium stearate for Compaction) 2.Oil binder mineral oil, isopropyl myristate, lanolin derivatives 3. Water-soluble binders (a) Aqueous solution gums (b) Aqueous solution of synthetic or Semi synthetic gums tragacanth, karaya, Arabic polyvinyl pyrrolidine (PVP),methyl cellulose Carboxy methyl cellulose (CMC) (c ) Preservatives are added along with gum to avoid microbial growth 4. Water-repellant binder. Mineral oil, fatty esters, derivatives of lanolin. Wetting agent is also used for uniform (These materials are used in combination with distribution of moisture 5. Emulsion binder water) Triethanolamine stearate, non-ionic emulsifiers, glycerol Monostearate. Preparation of Compacts: Compact powders are prepared by three methods. They are: (a) Wet Method (b) Dry Method (c) Damp Method, (a) Wet Method: The basic material (i.e., powder), colour and binders are formulated in the form of paste with the help of water. Then the pastes are pressed into moulds and slowly the products are dried by air. This method is not widely used, as there is a possibility of producing cracks and other faults in the preparation. (b) Dry Method: In this method, the basic materials and binders are compressed in special presses with the help of pressure. This method is carried out under controlled conditions. Examples:  Mixture of ammonia, stearic acid and starch.  Mixture of stearic acid and starch  Mixture of sodium stearate, lanolin and cetyl alcohol or  Mixture of triethanolamine stearate, lanolin and cetyl alcohol. (c) Damp Method: This method is most widely used for commercial purposes. The base powder, colour and perfume are properly mixed to form a mixture. Then liquid binder i.e., aqueous mucilage or mucin rich emulsion (oil-in-water type) are added to the mixture. Then it is properly blended until the desired plasticity of the product is obtained. Screening of mixture is carried out followed by compression by machine. Finally, the product is dried at elevated temperature. Formula 1 (Without Binder) Talc (slip character) Kaolin (covering materials) Titanium dioxide (covering materials) zinc stearate (slip character) Color Perfume (odour) Binder (with Binder) gum Arabic ( water-soluble Binder) Glycerol (emulsion Binder) Water (vehicle) Preservatives Quantity for 100 g 69 g 18 g 8g 5g q. s q. s q. s 1g 5g 94 g q. s Formula 2 (Without Binder) Talc (slip character) Calcium carbonate (absorbent) zinc oxide (covering materials) c (slip character) Color Quantity for 100 g 79 g 9g 7g 5g q. s Perfume (odour) Binder (with Binder) Gum tragacanth ( water-soluble Binder) Glycerol monostearate (emulsion Binder) Mineral oil (oil binder) Sorbitol Water (vehicle) Preservatives q. s q. s 2g 6g 4g 5g 83 g q. s Method: The method is same as that of face powder but here binders are incorporated in the formulation. 3. Body powder/ talcum powder/ dust powders: These powders are most widely used preparation for multiple purposes. They contain covering materials, adhesives, absorbency material, antiseptic and perfumes. The main function of body powder is absorption of perspiration (sweat). Due to the presence of fat film in the body powder, they adhere to the surface of the skin. Properties:  They should provide good slip character to the skin.  They should provide cooling and lubrication effect to the skin.  They should be able to prevent irritation of the skin. Ingredients: Ingredients which are used in the formulation of body powders are as follows: Ingredients 1. Metallic compound Example zinc stearate, aluminium stearate, magnesium carbonate(light), precipitate 2. Antiseptic materials calcium carbonate (chalk) Boric acid, chlorohexidine diacetate, They are incorporated in the formulation in bithional order to prevent the growth of microorganism which are responsible for the development of perspiration (sweat) and odour. 3. Adsorbent material Kaolin, magnesium carbonate, 4. Slip character 5. Adhesive materials precipitate chalk, starch Talc, zinc stearate Kaolin, zinc oxide, magnesium stearate Formula Talc (slip character) Colloidal kaolin (adhesive material) Colloidal silica (binding agent) Magnesium carbonate (absorbent) Aluminium stearate Boric acid (antiseptic) Perfume (odour) Quantity for 100 g 75 g 10 g 5g 5g 4g 0.3 g 0.7 g Method: Initially perfume is mixed with magnesium carbonate (absorbent) properly. This mixture is kept aside for some time. This is mixture A. Talc, colloidal kaolin, colloidal silica, aluminium stearate and boric acid are mixed together. This is mixture B. Mixture A is added to mixture B and then mixing is carried out properly. Then the preparation is passed through a sieve. Finally, the product is packed in a suitable container. Formulation: Formula Talc (slip character) Calcium carbonate (absorbent) Zinc stearate (slip character) Boric acid (antiseptic) Perfume oil (odour) Quantity for 100 g 70 g 25 g 4g 0.3 g 0.7 g Method: Perfume oil is mixed with calcium carbonate (absorbent) properly. This mixture is kept aside for some time. This is mixture A. Talc, zinc stearate and boric acid are mixed together. This is mixture B. Mixture A is added to mixture B and then mixing is carried out properly. Then the preparation is passed through a sieve. Finally, the product is packed in a suitable container. 4.3 Evaluation of powders Evaluation is carried out in order to know the quality of the finished product. General tests include determination of contents in the formulation along with the stability test. This is carried out to know whether the product remains stable for prolonged period of time (i.e.1 shelf life). Other tests are also carried out. They are: 1. Shade Test 2. Colour Dispersion Test 3. Pay-off Test 4 Pressure Test 5. Breakage Test 6. Flow Property Test 7. Particle Size Determination 8. Abrasive Character 9. Moisture Content 1. Shade Test: In this test, the variations of colour shade is determined and controlled. It is carried out by spreading the powder sample on a white paper and appearance is observed which is compared with the standard one. Another method involves, applying powder sample and standard one with the help of puff on the skin and then comparing it. The puff used to perform this test is also used for the final product. Evaluation of colour is carried out by using artificial light. 2. Colour Dispersion Test: in this test, a sample of powder is spread on a white paper and with the help of magnifying glass., segregation or bleeding of the colour is observed. the colour should be properly distributed in the powder base of the formulation. 3. Pay-off Test: This test is carried out to check the adhesive property of powders with the puff. This test is mainly carried out on compact powders. 4. Pressure Test: For compaction purpose in compact powders, pressure required. Uniform pressure should be applied to avoid formation of air pockets, which will lead to either breaking or cracking of compact powders. This is because low pressure will make the compact powder soft, whereas high pressure will lead to formation of hard cake. With the help of penetrometer, uniformity of hardness of the cake is checked. This is done by taking the reading at different points on compact powder and then comparing them. 5. Breakage Test: In this test, compact powders are allowed to fall on a wooden surface from a height of about 8-10 inches. This is carried out several times and then checking is done to see whether any breakage has occurred on compact powder. If the compact powder remains unbroken, then it shows the resistance to travel and normal handling by the users. 6. Flow Property Test: This test is carried out maim} on body powders to determine their flow property (from the container upon usage). This intern helps in easy application of powder to skin. In this method, angle of repose of powder is measured by allowing the powder product to fall on a plate through a funnel. Then the height and the radius of heap formed is measured, and even the time taken for the powder to fall is noted. 7. Particle Size Determination: With the help of microscope, sieve analysis or by utilizing other techniques and instrument, particle size of powder product is determined. 8. Abrasive Character: Abrasive character of powder can be determined by, rubbing, the powder on a smooth surface of the skin. Then with the help of a microscope, the effects of powder are studied. 9. Moisture Content: Moisture content present in the powder can be determined by using following formula. Moisture Content % = Weight of water in sample × 5 Weight of dry sample This is usually carried out by using various suitable analytical methods. These methods are also suitable for determining limits for colour. 5. Nail Lacquers Definition: Nail lacquers or nail paints may be defined as viscous or semi-liquid preparations that are intended for the decoration of the nails of the fingers and toes. Nail lacquers form the most commonly used the most popular type of manicure preparations. Nail polishes are quite distinct from those of nail lacquers and are regarded as a type of manicure preparations that produce a gloss by means of huffing action. The action is mainly by causing abrasion on the surface of the nail and secondly by drawing more blood into the capillaries of the nail. Ideal Properties of Nail Lacquer: The ideal properties of a nail lacquer should be as follows:  It should be safe for the skin and nails and should not lead to any harmful effects.  It should be easy to apply and easy to remove.  It shall maintain its properties even during long storage. Hence, an efficient nail lacquer should possess consistent stability.  The most important property is that it should form a uniform and satisfactory film on the nails.  It should have good wetting and flow properties and should be viscous in nature in order to form an appropriate film.  The distribution of the colour should be uniform which can be achieved by using finely divided pigments that are uniformly ground and evenly wetted by the solvent.  It should provide a good shine on the nail on application.  It should possess sufficient adhesive property so that it may uniformly adhere to the nail without slipping.  It should possess the required flexibility so that it may not become brittle and crack upon application.  The surface should be sufficiently hard in order to prevent th6 effect of impact and scratch.  The drying time of the film should not be too rapid or too slow; say about - minutes without forming any bloom.  It should be able to preserve all these properties at least for a week after its application. 5.1 Formulation of nail lacquers The formation of an efficient nail polish may be based on the selection of a proper and an essential ingredient. The ingredients involved in the formation of a good variety of nail polish could be as follows: S.N. 1 2 3 4 5 6 7 8 Ingredients Film forming agents Resinous substances Dissolving solvent Dissolving solvent/co-solvent Plasticizing agents Coloring agent Nacreous/pearly pigments Miscellaneous substances Example Nitro cellulose, ethyl cellulose, vinyl polymers Aryl sulphonamide-formaldehyde Ether, ethyl acetate, amyl acetate, butyl acetate Ethyl alcohol, butyl alcohol d-butyl phthalate, n-butyl stearate 5% titanium dioxide (TiQ2) Guanine crystal (1) suspending agent (2) perfumeries 1. Film Forming Agents: The selection of a film forming agent is an important step in the formation of a relevant type of nail lacquer. The most commonly used film forming substance is nitrocellulose, due to the following properties.  The films formed using nitrocellulose pigment stay flexible for a sufficient period of time.  It has good adherent property and hence does not allow any chipping and peeling.  Its solvent retaining capacity is very low.