Emollients in cosmetics

Emollient is one of the building block in cosmetics formulation.

1. Emollients in cosmetics Presented By - Payal Dnyaneshwar Borawake. M. Pharm SEM-II Guided By - Mrs. S.S. Mutha ( Asso. Prof. & HOD) Department of Pharmaceutics. PDEA’s S.G.R.S. College Of Pharmacy , Saswad. 1

2. contents Introduction Definition Need of an Emollients Dry Skin Ideal Characteristics Mechanism Of Action Classification Best emmolient How often and how much to apply Possible side effects References 2

3. Introduction The word emollient is derived from mollire which is a Latin verb meaning “to soften.” The term refers to materials that are able to soften the skin. Emollients are topical treatments. Emollients are sometimes known as Moisturizers , Refatteners. 3

4. definition CTFA dictionary defines emollients as, “cosmetic ingredients which helps to maintain the smooth and pliable appearance of the skin; emollients function by their ability to remain on the skin surface or in stratum corneum to act as lubricant, to reduce flaking, and to improve the appearance of the skin.” An emollient is a Humectant , a Lubricant and an Occluder . 4

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6. Examples of emollients Shea butter Cocoa butter Mineral oil Lanolin Petrolatum Paraffin Beeswax Squalene Coconut, jojoba, sesame, almond, and other plant oils Cetyl alcohol Olive oil (oleic acid) Triethylhexanoin 6 Lanolin Triethylhexanoin Cetyl alcohol

7. Need of an emollients Water constantly evaporates from the deeper layers of the skin called as trans epidermal water loss (TEWL). TEWL is normally about 4–8 g/(m²⋅h). When skin exposed to low humidity condition or when there is insufficient hydration from lower epidermal layers, there is excessive loss of water from stratum corneum. So skin becomes dry and for prevention or relief from dryness, emollients are needed. 7

8. Dry skin Dry skin is common symptom of number of skin conditions: - atopic dermatitis - irritant contact dermatitis - psoriasis Dryness aggravated by, frequent washing, use of harsh detergents and exposure to low humidity. If not treated, condition occur such as atopic eczema. Dryness is measure of water content of skin. 8

9. Dry skin (cont..) Etiology of dryness is removal of skin surface lipids, the horny layer lipids, and dissolution of hygroscopic water soluble components in corneum. So, state of hydration depends on: - Rate at which water reaches the horny layer. - Rate at which water leaves the skin surface. - Ability of S. Corneum to hold moisture. Hydration depends on “Natural Moisturizing Factor” (NMF). 9

10. Required qualities Easy to spread, pleasant feeling, non-oily or non-greasy. Appropriate rheological properties , Smooth texture. Provide effective hydration and prevent TEWL. Smoothens and softens the skin. Reduces dryness , improve dull appearance. Dermatological safe. No microbial contamination and growth. 10

11. Mechanism of Action Emollients trap moisture in the skin Some emollient contain lipids, like white soft paraffin , that act as an occlusive. Some emollients also contain ingredients like urea that act as humectants (attract moisture). 11

12. Classification / types 12 A] According to their Use : Soap substitutes Leave-on emollients B] According to greasiness : Ointments Creams Lotions

13. Classification/types C] According to chemical structure : Hydrocarbon oils and waxes – mineral oil, Petrolatum, Paraffin Silicone oils – Dimethyl, Methyl phenyl polysiloxanes Triglyceride esters – Vegetable and animal fats and oils Acetoglyceride esters – Acetylated monoglycerides Ethoxylated glyceride – Ethoxylated glyceryl monostearate Alkyl esters – Methyl ester of F.A., Hexyl laurate, isohexyl palmitate Alkenyl esters – Oleyl myristate /Stearate/ oleate 13

14. Classification (cont…) Fatty acids – Stearic, oleic, lanolin, palmitic acids Fatty alcohols – Lauryl, isostearyl , isocetyl alcohols Fatty alcohol ethers – Ethoxylated lauryl alcohol, cholesterol Ether-esters – Fatty acid esters of ethoxylated fatty alcohols Lanolin and derivatives – Lanolin oil, wax, alcohols, FA, isopropyl lanolate, acetate of lanolin alcohols, etc Polyols and polyether derivatives – Propylene glycol, glcerol , PEG-200, hexylene glycol, polypropylene glycol 2000 14

15. Classification (cont…) Polyol esters – Ethylene glycol mono- and di - fatty acid esters, polypropylene glycol 2000 mono oleate, mono Stearate Wax esters – Beeswax, spermaceti, myristyl myristate Beeswax derivatives – Polyoxyethylene sorbitol beeswax Vegetable waxes – Carnauba, candellia Phospholipids – Lecithin Sterols – Cholesterol, cholesterol FA esters Amides – FA amides, ethoxylated FA amides. 15

16. Soap substitutes 16 Soap should avoided in people with dry skin condition, soap substitute is used for cleansing purpose. They not remove natural oil in skin. Most emollients (except white soft paraffin alone) can be used as a soap Substitute. Soap substitutes can either be applied before bathing, showering or washing, or while in the water.

17. Leave on emollient 17 These emollients directly applied onto the skin and left on to soak in. They are not washed off the skin. Quantity of emollient required will depend on – - the size of the person, - the extent and severity of the skin condition, - whether the emollient is also being used as a soap substitute. As a general guide, if you needed to treat the whole body, the recommended quantities used are 600 g/week for an adult, and 250-500 g/week for a child.

18. Ointments Greasy in nature Made of Soft paraffin/ liquid paraffin. Ideal for dry, thickened skin. Applied at night time. Do not contains preservative, So no skin reaction. A tablespoon of any ointment can be dissolved in some hot water and added to the bath water. 18

19. 19 A layer of petrolatum applied to normal skin can reduce the TEWL by 50–75% for several hours.

20. Creams 20 Contains mixture of oil and water. Less greasy, easier to spread than ointments. Must be used frequently. Applied liberally to prevent drying of skin. Contains preservatives. Example : AproDerm Emmolient Cream. White soft Paraffin 15%, Liquid Paraffin 6%. Other Ingredients: Ceteareth-20, Macrogol Cetostearyl Ether, Cetostearyl Alcohol, Sodium Hydrogen Phosphate, Phosphoric Acid / Sodium Hydroxide, Euxyl PE 9010, Purified Water.

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22. Lotions Contains less oil and more water. Less effective in moisturization. Useful for hairy areas like scalp. 22

23. Lipophilic emollients & occlusives 23 Occlusive materials –Vegetable, mineral oil, natural /synthetic waxes, FA esters, lanolin oil & its derivatives. Mineral, vegetable oil, waxes- Heavy, greasy feeling. FA esters – Light, pleasant feel. - Chain length have impact on feel property. - Efficacious skin refatteners. Fatty acid mono & di- glycerides - -Prepared by trans esterification of triglyceride with glycerin. -Monoglycerides of stearic , lauric acid part of skin lipids. E.g. Glyceryl oleate.

24. Hydrophilic lipids Preferred for foaming skin cleansing preparations. Ethoxylation & propoxylation - more compatible. More the lipids ethoxylated , more soluble they are and less impact on foam. But also, less persistence on skin, weaker refattener . Examples:- Ethoxylated glycerides Low ethoxylated triglycerides Ethoxylated mono and di- glycerides Ethoxylated/ propoxylated fatty alcohols 24

25. Lanolin 25 Extracted from sheep wool grease. It is a complex mixture of esters of high mol. wt. lanolin alcohols and of lanolin FA. Lanolin alcohols & oil- Super fatting agents in soaps. Ethoxylation of hydroxyl groups gives hydrophilic compounds- useful emollient. E.g. PEG 75 lanolin Alkoxylated lanolin derivatives – reaction with mixture of propylene and ethylene oxides.

26. Lecithin Natural mixture of polar & neutral lipids. Vegetable source is soyabean , maize. Animal source is egg yolk. Have emollient, refattening , moisturising properties. Bare lecithin – Secondary product of soya oil extraction, contains 60-70% polar lipids & remaining 25-30% soya oil. Raw lecithin further fractionated, purified & modified . 26

27. Silicone derivatives Predominant silicones used are dimethicones. Length of dimethylsiloxane polymer chain dictates M.W. and viscosity. Viscosity ranging from about 100 to several thousand centistokes. High to medium mol. wt. are occlusive, skin protective. Low mol. wt. are dryer emollients. Non polar silicones require hot emulsification process. 27

28. Best Emollient There is no best emollient. The type to use depend on - Dryness of your skin, Area of skin involve and Preference. For example : If there is mild skin dryness and no flare-ups, a lotion or cream may be best. If there is moderate-to-severe dryness, a thicker cream or an ointment is usually best. Creams are usually less messy but need to be put on more often than ointments. A lotion or spray is best for areas of hairy skin. For areas of weeping eczema, a cream or lotion is best as ointments will tend to be very messy. 28

29. How often emollient should apply Emollients applied whenever the skin feels dry and as per need. This may be two to four times a day or more. Applied immediately after washing or bathing when skin has been dry. Emollients can and should be applied at other times during the day, i.e. in extreme weather to provide a barrier from the cold. We should continue to use emollients after skin condition has cleared if the clinical condition justifies continued use. 29

30. How much to apply 30 The quantity of leave-on emollient required will vary depend on the  size of the person,  the severity of the skin condition, and  whether the emollient is also being used as a soap substitute. As a general guide, If needed to treat the whole body, the recommended quantities are: - 600g per week for an adult, - 250-500g per week for a child under 12.

31. How much to apply Area of body Creams or ointments Lotions Face 120 g 100 mL Both hands 120 g 500 mL Scalp 500 g 1000 mL Both arms & legs 500-1000 g 1000 mL Trunk 1000 g 1500 mL Groins 120 g 500 mL 31

32. Precautions to take Paraffin-based emollients are flammable so care should taken near any open flames or potential causes of ignition, such as cigarettes. Ointments and creams used in the bath and shower can make the surface slippery so extra care should be taken. If you find an emollient is making your skin sore and/or very itchy, you may be allergic to one of the ingredients and you should discuss this with your doctor or nurse. If you are having ultraviolet light treatment or radiotherapy, ask for specific guidance on emollient use as instructions may differ slightly. 32

33. Possible side effects 33 Irritant reactions : These include an overheating, 'burning' sensation or stinging. It is usually caused by a reaction to a certain ingredient contained in the cream or lotion. If the stinging is painful and continues, try a different emollient. Folliculitis: Some emollients that work by sealing wounds or cracks in the skin with a protective barrier (occlusive) can occasionally cause hair follicles to become blocked and inflamed (folliculitis) and cause boils (painful, red bumps on the skin). Facial rashes : Some facial emollients can cause rashes on the face and can aggravate acne (a skin condition that occurs on the face and commonly affects people during their teenage years).

34. References M.S.Balsam , E. S agarin . Cosmetics-science and technology. Krieger Publishing Company, Second edition, Volume 1, Pg. no.- 27-78. P.P.Sharma . Cosmetics-Formulation, manufacturing & quality control, Vandana Publications Pvt. Ltd., 4 th edition 2008, Pg. No.- 105-110. M. P aye , A.Barel , H.Maibach . Handbook of cosmetic science and technology, Special Indian Edition, 1 st edition 2008, Pg. No.248-254. https :// www.healthline.com/health/emollient . 34

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