Emollients, rheological additives and antimicrobial used as preservatives

Emollients, rheological additives classification and application, preservatives used as o antimicrobial agent in cosmacuticals

1. Presented by:- Pramod V. Pise Emollients, Rheological additives and Antimicrobial

2. Moisturizers or emollients are complex mixtures of chemical agents specially designed to make the external layers of the skin softer and more liable. Emollients are safe and effective – a good skin care routine using emollients can smoother, moisturise , and protect the skin, so helping to reduce the number of eczema flares. The emollients in this factsheet are available on prescription, and can also be bought over the counter from a pharmacy Introduction

3. Emollients trap moisture in the skin and form a protective oily layer on the outer skin surface which helps skin repair and improves skin hydration. And keep the skin soft and moist. Mechanisum of emollients

4. Most people get dry, irritated skin from time to time, especially during the winter when the air is cold and dry. You can also get dry skin from washing your hands often, or from working with harsh chemicals. Emollients are effective for soothing and healing dry skin due to almost any cause. What are the benefits of an emollient?

5. Paraffin-based emollients are flammable so please take care near any open flames or potential causes of ignition, such as cigarettes. 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 Ointments and creams used in the bath and shower can make the surface slippery so take extra care. What precautions should I take with emolients ?

6. Emollient type according to use Soap substitutes Soap is very drying for the skin and should be avoided in people with dry skin conditions. Any emollient (except white soft paraffin alone) can be used with water to cleanse the skin, as they do not remove the natural oils in the skin. Leave-on emollients These emollients are applied directly onto the skin and left on to soak in. They are not washed off the skin (as with soap substitutes). Types of emollients

7. Ointments These are greasy in nature. They are usually made of white soft paraffin or liquid paraffin, and are ideal for very dry or thickened skin and night-time application. They do not usually contain preservatives (ingredients that help to protect the product from bacteria/germs and increase its shelf-life) and are therefore less likely to cause skin reactions. Creams These contain a mixture of oil and water and are less greasy, and therefore easier to spread on the skin than ointments. They must be used frequently and applied liberally to prevent the skin from drying out. Creams usually come in a container with a pump dispenser and are good for day-time application . Emollient type according to greasiness

8. Lotions These contain the least oil and most water so are the least effective in moisturizing the skin. They normally contain preservatives so may cause skin irritation. Lotions are useful for hairy areas such as scalps and areas of weepy skin. Hydrating gel Gels are formed from molecules that make a three-dimensional network, which then traps other molecules in the spaces of the network. They are relatively light and non-greasy, despite having a reasonably high oil content. They should be applied every 3–4 hours.

9. Rheology is the science of flow. Every time a lotion is poured, a cream squeezed from a tube or a lipstick applied, rheology is involved. Even when products are at rest, it plays an important part in controlling stability and suspension. The rheology of a system is described in terms of its viscosity. Viscosity is the resistance to flow and defined as viscosity = shear stress/ shear rate Shear stress is the force per unit area applied and shear rate is the resulting velocity gradient. Rheological additives for emolients

10. Aqueous phase additives Rheolux associated thikeners Hectorite Bentone hydrofillic clays Non aqueous phase additives Bentone organophilic clays Bentone gel Thixcine R rheological additive Classification

11. The properties imparted by the rheological additives benefits different cosmetics in different ways Stick product (lipstick and antiperspirant) maintain homogeneity in molten and setting stages Increased high- temperature integrity eliminate oil migration reduce creasing around lips and eyes Mascara improve film build increased water –resistance eliminate oil migration Applications of rheological additives

12. Emulsion Improve emulsion stability Enable cold process emulsification Create novel viscosity effect UV Sunscreen Eliminate ultrafine Ti02 skin whitening problems Enhance sun protection factor (SPF) Optimize use of sunscreen actives Reduce separation and settlement

13. Preservatives are use to prevent spoilage of cosmetics product there are two main reasons for spoilage i.e , oxidation of oil and fat and microbial growth Microbes such as bacteria, fungi, yeast are widely distributed in nature. Sources of microbial contamination are included raw material ,environment, equipment, packaging materials and personnel. If microbes are allowed to multiply in finished cosmetics , they will utilized cosmetic ingredients for their growth and metabolites produced will interfere with the ingredients present and thus the product will be spoiled. Antimicrobial used as preservatives

14. Types and examples Organic acid Benzoic acid, p- hydroxy benzoic acid, propionic acid, sorbic acid . Alcohols ethyl alcohol, isopropyl alcohol, phenyl ethyl alcohol, chlorbutamol . Aldehydes Formaldehyde , cinnamic aldehyde . Phenolic compound cresol,methyl chloro thymol,phenol,bis-phenol,o - phenyl phenol. Esters Methyl p- hydroxy benzoate,butyl p- hydroxy benzoate. Mercury compounds Thiomersol,nitromersol,phenyl mercuric salts e.g acetate. Surface active agents Benzathonium chloride , cetyl pyridinium chloride. Miscellaneous compound Vanillin ,ethyl vanillin,5 bromo-5 nitro-1,3-dioxane

15. MECHANISUM OF ANTIMICROBIALE CHEMICAL AGENT MECHANISUM OF ACTION ASCORBIC ACID Oxygen scavenger CITRIC ACID Enzyme inhibitor/ metal chelator SULFITES Enzyme inhibitor/ oxygen scavenger ACETIC ACID Disrupt cell membrane function BENZOIC ACID Disrupt cell membrane function/ inhibit enzymes NITRATES Inhibit enzyme/ disrupts cell membrane function PROPIONIC ACID Disrupt cell membrane function

16. They have Wide range of compatibility Do not become rancid or support microbial growth. Non- irritating (to the same degree of lanolin, petroleum , etc) Adhere well to the skin Easily washed off Low incidence of sensitization They are easier to spread They can absorbed a large quantity of water or aqueous substances. They have advantages on absorption bases as they asist oil soluble medicaments to penetrate the skin ADVANTAGES

17. Sometimes undergoes gradual discoloration with certain drugs Unless cetyl alcohol is added, an aqueous solution is added only to the extent of 5 percent Volatility and flammabilty Effectiveness is reduced by organic materials such as blood ,mucus, excreta. Major signs of instability i.e. colour change, precipitation, microbial growth chemical gas formation Disadvantages

18. 1.Dissociation and pH Different types of cosmetics have different pH and different micro-organism can grow at different pH One types of micro- organism grow in acidic medium while other type may grow in alkaline pH Preservatives which are active in both acidic and alkaline pH ranges have the disadvantages of being highly reactive in nature For examples formaldehyde and formaldehyde releasing compounds Various preservatives which are greatly influenced by PH Activity of weak acid depends on their undissociated amount of acid which in turn depends on their dissociation constant and Ph of the system . Some preservatives may be ph dependent because of the stability problems e.g 2-nitro-2- bromo - propanediol start deteriorating at Ph higher than 7 Factors affecting microbial preservatives efficacy

19. Some materials used in cosmetics formulations have antimicrobial action and therefore, concentration of preservatives required may be very less There may be ingredients in cosmetics which promote growth of micro-organism for examples mucilages of natural gums Recommended effective concentration range from as little as 0.001% (organic mercury compounds ) to 0.5 to 1.0% (weak acids) Concentration of preservatives may be reduced if more than one preservatives is used in combination, some commonly used preservatives are used as anti-microbial agents 2. Concentration Name concentration % Benzoic acid 0.5 Salicylic acid, formaldehyde 0.5 bronopol 0.1 Benzalkonium chloride 0.25

20. Different antimicrobial agents have different activity against microbes. For examples , hydroxy benzoate are active against moulds, fungi, and yeasts but less active against bacteria Chlorobutanol has antibacterial and antifungal activities Phenyl mercuric nitrate is active bacteria, fungi, moulds and yeast 3. Susceptibility of organism

21. 4. Interference by ingredients of cosmetics Several nonionic surfactant such as tween 80, polythethylene glycol 1000 monocetyl ether , polyethylene glycol 400 interfere with activity of preservatives by exerting protective effect on micro- oragnisms Soap and anionic surfactant in lower concentration promote growth of gram negative bacteria 5. Influence of solid particles A number of cosmetics preparations contain insoluble solid particles these are koalin , chalk,,zinc oxide , talc and pigments. Preservatives can be absorbed on the surface of the solid particles. Preservatives can also interact with plastics. Phenolic and quaternary ammonium compounds have been reported to react with polyurethane.

22. Thank you