Education and Research, Bhagat Phool Singh Mahila Vishwavidalaya, Khanpur, Kalan, Sonipat

morning till night, cosmetics play an important role and have a significant effect on our daily routine. Cosmetic scientists keep working to develop safe, attractive and efficacious new formulation. Since ancient times, both males and females are commensurate competitors for enhancement of appearance.

Men used animal parts and leaves of the plants to decorate themselves whereas Women did so by using coloured stones and flowers on body parts. In India, cosmetics are regulated by the Central Drugs Standard Control Organization (CDSCO) under the Ministry of Health and Family Welfare. According to CDSCO, cosmetics is any product which is used topically on various external parts of the human body such as nails, lips, teeth and mucous membrane etc. with a view of cleansing, protecting, perfuming and keeps them in good condition 1 .

In India, cosmetic science involves research and development of safe and effective cosmetic products, as well as the regulatory and quality control aspects of the industry. It involves study of composition, development of formulation, stability testing, evaluation of safety and efficacy, packaging and labelling of formulation and execution of regulatory guidelines. The objective of cosmetic is to develop products that are used for beautification of consumers while maintaining their safety and quality 2 .

In the United States, the regulatory body for cosmetics is the Food and Drug Administration (FDA). The FDA regulates cosmetics under the Federal Food, Drug, and Cosmetic Act, it defines cosmetics as “articles intended to be rubbed, poured, sprinkled, or sprayed on, introduced into, or otherwise applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance.” The FDA has established regulations for cosmetic labelling, safety, and good manufacturing practices to ensure that cosmetic products are safe for consumers. Recently, cosmetic science has undergone great heights with involvement of natural and organic ingredients, long-lasting with ethical considerations 2 .

COSMETIC CLASSIFICATION Cosmetic can be classified in various classes depends upon their product type, regulatory, formulation and ingredients etc. (Table 1). Table 1: Cosmetics having their use and formulation Facial Cosmetics Hair Cosmetic s Eye Cosmetics Dental and Oral Cavity Cosmetics Deodarants Miscellaneous Cosmetics Cleansing Preparatio n Hair dye Eye liners Tooth paste Lotions, Powders Blackhead removers Skin Nourishing Hair oil Eye gloves Mouth washes Creams Toilet soaps Skin Tonic Hair Creams Kajal Teeth whitening Anti-stress marks remover 1.

Classification of cosmetics based upon their product type Cosmetics can be categorized into different classes based on their use and formulation:- a) Makeup: Cosmetics applied to the eyes, face, lips, and nails to reinforce one’s appearance. e.g., eye shadow, mascara, lipstick, foundation, nail polish, and blush. b) Skin care: Cosmetics used to enhance the skin care. Examples include toners, anti-aging products, moisturizers, cleansers, serum. c) Hair care: Cosmetics used to clean, condition, style, and color the hairs, e.g., shampoo, conditioners, gels, hairspray and dye. d) Fragrance: Cosmetics used to compute pleasant fragrance to body or the place, e.g., perfumes, colognes, body sprays, and scented candles. e) Personal care: Cosmetics used for hygiene and rebuke desire, e.g., deodorants, mouthwash, toothpaste, body wash and shaving cream. f) Oral care: Cosmetics used to keep oral hygiene and freshness, e.g., toothbrushes, mouthwash, toothpaste and dental floss. g) Baby care: Cosmetics that are produced for the gentle skin of infants and young children, e.g., baby shampoo, baby oil, diaper cream, and baby lotion. 2. Classification of cosmetics based on Regulation a) Over-the-counter (OTC) drugs: Cosmetic products that encompass active ingredients that are regulated by the US Food and Drug Administration (FDA) as drugs, such as OTC acne treatments, antiperspirants, and sunscreens. b) Cosmeceuticals: Cosmetic products that encompass bioactive ingredients used to give medicinal or therapeutic benefits, such as anti-aging creams, skin-lightening products, and hair growth serums. c) Medical devices: Cosmetic products in medical purpose for diagnosis, treatment, or prevention of ailment, such as laser hair removal devices, light therapy devices for acne, and microdermabrasion machines. d) Natural and organic cosmetics: Cosmetic products that are produced with natural or organic ingredients and are advertised as free from synthetic chemicals and preservatives.

Natural and organic cosmetics are not regulated by the FDA, but they may be certified by third-party organizations, such as the USDA or NSF. e) Conventional cosmetics: Cosmetic products that are produced with synthetic chemicals and are not used to give any therapeutic or medicinal benefits beyond traditional cosmetics. Conventional cosmetics are not regulated by the FDA, but they must adhere with labeling and ingredient requirements 3 . 3. Classification of cosmetics based upon formulation a.) Creams and lotions: Cosmetic products that are emulsions of oil and water.

Creams are thicker and heavier in consistency, while lotions are flowing and lighter. b.) Serums: Cosmetic products that are light weighted encompass good concentration of active ingredients. Serums are designed to permeate deeply into the skin for maximum effect. c.) Gels: Cosmetic products that have a jelly-like consistency. Gels can be produced for various skin conditions, such as acne, hydration, or cooling. d.) Powders: cosmetic products used for makeup application.

Powders can be pressed or loose and can be used to set makeup or provide coverage. e.) Lipsticks and lip glosses: Cosmetic products applied on the lips for coloration and shining. Lipsticks are generally more opaque, while lip glosses are more steep and shiny. f.) Mascara: Cosmetic product applied to the eyelashes to improve length, thickness, and color. g.) Nail polish: Cosmetic product applied to the nails for coloration and shining. h.) Shampoos and conditioners: Cosmetic products used for hair cleansing and conditioning. Shampoos are designed to abolish dirt and oil, while conditioners are designed to moisturize and detangle hair. i.) Sunscreen: Cosmetic product used to safeguard the skin from the deleterious effects of the sun.

Sunscreen can be designed as lotion, cream, gel, or spray. j.) Cleansers: Cosmetic products used to abolish dirt, oil, and makeup from the skin. Cleansers can be designed as gels, foams, creams, or oils. k.) Face masks: Cosmetic products applied to the face for various purposes, e.g., deep cleansing, exfoliating, or hydrating. Face masks can be formulated as creams, gels, or sheet masks 3 . 4.

Classification of Cosmetic based on Ingredients:- a) Retinol-based products: Cosmetic products that encompasses retinol or its derivatives, which are known to enhance the appearance of fine lines, wrinkles, and hyper pigmentation. b) Vitamin C-based products: Cosmetic products that encompass vitamin C, known for its antioxidant potential and ability of skin brightening. c) Hyaluronic acid-based products: Cosmetic products that encompasses hyaluronic acid, known for hydration and plumping the skin. d) Salicylic acid-based products: Cosmetic products that encompasses salicylic acid, known for exfoliating and unclogging pores, making it particularly effective for acne-prone skin. e) Glycolic acid-based products: Cosmetic products that encompasses glycolic acid, known for exfoliating and improving the texture and tone of the skin. f) Aloe vera based products: Cosmetic products that encompasses aloe vera, known for soothing and hydrating properties, making it particularly impressive for sensitive and dry skin. g) Charcoal-based products: Cosmetic products that encompasses activated charcoal, which is known for its ability to draw out impurities and toxins from the skin, making it particularly effective for oily and acne-prone skin. h) Niacinamide-based products: Cosmetic products that encompasses niacinamide, known for its ability to enhance tone and texture of skin, reduce the appearance of fine lines and wrinkles, and balance sebum production. i) Squalane-based products: These are cosmetic products that contain squalane, which is known for its ability to deeply moisturize the skin without clogging pores or causing breakouts. j) Tea tree oil-based products: Cosmetic products that encompasses tea tree oil, known for its antibacterial and antiinflammatory properties, making it specifically effective for treating acne and other skin conditions COSMECEUTICALS Cosmeceuticals are new category for cosmetic products which are used for both cosmetic as well as for therapeutic purposes. These cosmetic products encompass active pharmaceutical ingredients, which have shown pharmaceutical effects on the skin. “Cosmeceutical” term was first time coined by Albert Klinman, a dematologict from the University of Pennsylvania in 1984. The use of Cosmeceuticals has become continuously increased results in significant growth of these products in the market.

Cosmececuticals differs from traditional cosmetics is that they have good penetration ability in the skin and affect skin’s function. Moreover, these products can be sold without a prescription for topical use only4. These products have achieved significance as it acts as a bridge between cosmetics and pharmaceuticals.

They are assumed to be more safer than pharmaceuticals and more effective than traditional cosmetics. Therefore, it serves as a suitable alternative for the customers who do not want to visit to dermatologist or treat the skin ailments without prescription. Classification of cosmeceuticals Cosmeceuticals are classified depends upon their use, formulation and pharmaceutical active ingredients (Table 2):- Based upon their use a) Anti-aging cosmeceuticals:- These products are formulated to decrease the apparent gesture of aging, e.g., fine lines, age spots and wrinkles.

These products encompass ingredients that enhance the production of collagen and improvement in skin elastic nature, leads to rigid and young appearance. Common ingredients found in anti-aging cosmeceuticals include Vitamin C, Retinoid, Hyaluronic acid, peptides and hydroxyl acid.. These cosmetics are found in different formulations like creams, masks and serums. “Table 2:- [Classification of cosmeceuticals]” Cosmeceuticals Use Formulation Pharmaceutical active ingredients Anti-aging Acne fighting Moisturizing Sun Protection Skin brightening Serums Creams Gels Masks Retinoid Hydroxy acid Vitamin C Peptides Niacinamide b) Acne-fighting cosmeceuticals:- These cosmeceuticals are formulated to cure and avoid acne breakouts by decreasing inflammation, unclogging pores and regulating production of oil.

These cosmetic encompasses active components that destroy acne producing bacteria, decrease signs of inflammation results in improving the complete skin appearance. Common ingredients found in such cosmetics include salicylic acid, retinoid, benzoyl peroxide, hydroxyl acids and tea tree oil. c) Moisturizing cosmeceuticals:- These products are formulated to provide hydration and nourishment to skin. These cosmeceuticals contain component which helps to retain moisture and protect the skin from environmental factors that results in dehydration or dryness and destruction of skin.

Common ingredients present in these products are ceramides, glycerin, hyaluronic acid and natural oils. d) Sun Protection Cosmeceuticals:- These cosmeceuticals are produced in such a way that they protect our skin from deleterious effect of UV rays from the sun. If exposure of UV rays occurs for long duration, it can cause sunburn, risk of skin cancer and premature aging. These products are made up of the ingredients which functions in a joint manner to avoid or block UV radiation.

Moreover, these cosmeceuticals contain antioxidants which neutralize the free radicals produced by overexposure of UV rays. Common ingredients present in this category include Zinc oxide, titanium oxide, antioxidants etc. It is important to use a cosmeceutical for sun protection should have a SPF (Sun Protection Factor) factor of 30 or above 30 4.

Formulation Based Cosmeceuticals a) Serum cosmeceuticals: It is a type of cosmeceuticals that contain higher amount of active constituents in a lightweight, easily absorbed composition. These are formulated to provide potent dose at the targeted site in treatment of skin ailments. Common types of serum include Niacinamide serum, Vitamin C serum, Peptide serum stc.

Serum are either used alone or in combination with other cosmeceuticals for skin care. b) Cream cosmeceuticals:- These are most popular type of cosmeceuticals used in moistening and protection of skin and also administering to targeted site for specific skin disease. These cosmeceuticals particularly contain pharmaceutical active ingredients, moisturizer and emollients to give an equilibrium between hydration and cure. Some examples include Sun protection, Moisturizing cream, brightening cream etc. c) Lotion cosmeceuticals:- This is another popular cosmeceuticals and commonly it is used for moisturizing and curing purpose.

These are specifically lightweight and fast-absorbing executing it as a favorite option for all types of skin. d) Gel formulation cosmeceuticals:- These cosmeceuticals are commonly used as they are light weighted and provide non-greasy use easily penetrate the skin. Gels also deliver active ingredients to skin as they provide stable and consistent dispersion of particles. Examples of gel cosmeceuticals are sunscreen gels, eye treatment gel, acne treatment gel. e) Mask formulation cosmeceuticals:- Cosmeceuticals masks are used topically on the face for a specified time to embellish the look and skin health.

These masks encompass vitamin C, antioxidant and exfoliating agent that permeate more deeper in skin to give good health benefits. Most commonly used mask cosmeceuticals in market include clay masks, sheet masks, orange peel-off masks, aloe-vera masks etc 3. There are some differences for the distinction of cosmeceuticals and cosmetic given in Table 3.

Table 3: Differentiate between cosmeceuticals and cosmetic S.No . Cosmeceuticals Cosmetics 1 . 2. 3 . 4 . 5. 6. 7. Cosmeceuticals can improve and enhance the skin’s appearance by using biologically active ingredients Active principles can pass through the epidermis.

Designed to have long-term, clear effects. Cosmeceuticals are more concentrated, pure and more effective giving pharmaceuticals benefits. Cosmeceuticals products give slow but permanent results.

Cosmeceuticals have ingredients that have rejuvenating properties. Examples: Serums, creams, and dermaceutical products. Cosmetic can applied to the outer surface of the skin.

It can maintain, protect and clean. Alters the appearance and external feel of the skin for a short time. Cosmetic products only deliver their ingredients at a very superficial level into the skin for beauty and style.

Results through cosmetics are immediate and fast. Cosmetics do not heal your damages they only cover up. Examples: Makeup, hair care, skin care DEFINITION OF COSMETICS AS PER INDIAN REGULATIONS Cosmetic” means any article intended to rubbed, poured, sprinkled or sprayed on or introduced into, human body or any part thereof for cleansing, beautifying, promoting attractiveness, altering the appearance and includes any article intended for use 4 .

DEFINITION OF COSMETICS AS PER EU REGULATIONS A cosmetic product is any substance or mixture intended to be placed in contact with the external parts of the human body, or with the teeth and mucous membranes of the oral cavity, with a view exclusively or mainly to cleaning them, perfuming them, changing their appearance, protecting them, keeping them in good condition or correcting body odours 4. EVOLUTION OF COSMECEUTICALS FROM COSMETICS The evolution of cosmetics is a long and interesting story that continues for centuries. From thousands of years, people have been made use of cosmetics for different purposes, like religious, personal grooming and for good appearance.

As time goes, evolution in the ingredients, formulations and manufacturing processes takes place and the belief that cosmetic is a luxurious item has changed to a necessity. For centuries, cosmetics were formulated using different sources of drugs such as plants, minerals and animal origin e.g., Egyptian women used kohl for eye darkening and henna for dying hairs. Greeks and Roman women used powders and chalk contains lead for whitening their faces.

In the middle age, the use of the cosmetic goes as they were linked with conceit and criminal devious. However, use of cosmetic cameback in Renaissance period, when Queen Elizabeth 1 of England promote lead based white face panit and bright red lipstick. In 20 th century, the cosmetic made available to general public and growth and novelity in cosmetic industry has been observed.

In the year 1920, flapper culture promoted a new way of makeup that contains dark eyeliner, red lipstick and rosy cheeks. In 1950s, the discovery of mascara and liquid foundation comes as a boon in the cosmetic industry as it helps in easy application as well as enduring in makeup 3 . Nowadays people’s altitude are moving towards use of natural and organic cosmetics due to the side effects associated with synthetic chemicals.

This approach has came into light new category of cosmetics “green beauty”, involves the products designed from natural and organic components and have environmental friendly packaging. The evolution of cosmetics can be considered from long back in centuries where cosmetics were used for beautification purpose. In Egypt, kohl a preparation made from lead, copper and ash was used for eyes to produce dramatic effects.

In Rome, Women used face powder having lead for yellowish complexion, while in China, smooth and even skin tone has been achieved by using rice powder 3 . The evolution of cosmetics has been carried by merging of techniques development, alteration in user’s choices and developing knowledge regarding the skills of cosmetic products. As we know about the chemical components and the necessity of users, it is obvious that there will be progression and modernization in the cosmetic industry.

Overall, the evolution of cosmetics has shown alteration in social and cultural attitude towards beautification and self-expression. There are major evolutionary milestones in Cosmeceuticals given in Table 4. Table 4: Major milestones in evolution of Cosmeceuticals S.No .

Years Evolution 1. 2. 3. 4. 5. 6. 1980s 1990s Early 2000s Late 2000s 2010s Present day The term “Cosmeceutical” was coined by Dr. Albert Kligman, used to define cosmetic products have pharmaceutical-like benefits. Retinoids, derivatives of vitamin A, popular product helps for reduction in fine lines and wrinkles.

Antioxidants, a source of vitamin C, and extract of green tea gained importance due to their role in protecting the skin from environmental changes. Growth factors, such as proteins (Cosmeceutical ingredients) were recommended that increase cell growth and cell differentiation. Stem cells and DNA repair enzymes has been introduced for their ability to repair and regenerate the skin.

With the improvement in personalized skin care, cosmeceutcals products are designed to cure particular skin disease like hyperpigmentation, acne, and acne use of plant- based ingredients such as plant extracts and essentials oils has gained popularity in Cosmeceutical products. COSMETICS AS OTC DRUGS Cosmetic and over the counter (OTC) drugs are two classes which are regulated in different manner. Still, there are examples where one product cascade in different classes based on their intended use and special assertion.

Cosmetics :- these are the basic products which are used for increasing and changing the presentation of body of the human. These products are not used in prevention, diagnosis and cure of any ailment. Common examples of cosmetic products such as skin care creams, hair products, lotions, perfumes etc.

Cosmetics particularly give attentions on subjects like beautification, fragrance, cleaning and maintenance of the body. The primary regulatory framework for cosmetics in the European Union is Regulation (EC) No. 1223/2009. Over the counter drugs :- OTC drugs are those pharmaceuticals that can be buy by people without the prescription.

These products are used for used to prevent, cure and relief of minor diseases and medical condition. OTC drugs are subjected to complete testing and checking so as to ensure safety, efficacy and proper labelling. These products either contain single component or combination of components which are used for therapeutic purposes.

Examples of OTC drugs are pain reliever, cough and cold syrup, antacids, antifungal creams and analgesics. Dual category products :- In few instances, any products have cosmetic as well as OTC drugs quality. These products are known as “Cosmeceuticals” or “Dermaceuticals”.

They are formulated in such a way that they can be used for cosmetic purpose as well can be have therapeutic activity for skin and hair. For example, anti-aging creams (to reduce wrinkles and improvement in skin quality) can be categorized as Cosmeceutical. Regulatory considerations : There are the varying regulatory requirements for cosmetics and OTC drugs.

Cosmetics in the European Union are regulated under Regulation (EC) No. 1223/2009, which provides attention on ensuring product safety, appropriate labelling, and in accordance with Good Manufacturing Practices. On the other hand, OTC drugs, need more endorsement from regulatory bodies, like European Medicines Agency (EMA) or national competent authorities. OTC drugs are subjected to inclusive clinical trials, to ensure their efficacy, and receive marketing authorization before they can be sold as non-prescription pharmaceuticals 2 .

COSMETICS AS QUASI DRUGS Cosmetic products categorized under quasi-drugs are those that show some medicinal or therapeutic properties, but are not considered as developed pharmaceutical drugs. There are different regulations required to be fulfilled for Quasi drugs indifferent countries. Quasi-drugs, also known as “quasi-medicinal products” or “quasi-pharmaceuticals,” are cosmetic products that provide certain health benefits or claim to alleviate or improve specific conditions.

These products are used not only for traditional cosmetic purpose, but also provide help in prevention, improvement, or treatment of certain skin or hair conditions. In Japan, quasi drugs are regulated by Pharmaceuticals Affairs Law(PAL). The manufacturer must provide scientific evidences and testing procedures to ensure safety and efficacy of the product.

In Japan, quasi drugs are approved by Ministry of Health, Labour and Welfare (MHLW). There must have complete data regarding ingredients, manufacturing process and labeling and clinical studies. Different quasi drugs along with ingredients and benefits are given in Table 5.

Table 5: Different quasi drugs along with ingredients and benefits S.No . Type of Quasi drugs or cosmetic Ingredients (with mechanism of action) Benefits (Claims ) 1. Skin Whitening creams Arbutin, kojic acid, or vitamin C, which are believed to inhibit melanin production and promote a more even complexion.

Lighten the skin tone and reduce the appearance of dark spots or hyperpigmentation. 2. Anti-acne treatment Salicylic acid, benzoyl peroxide, or tea tree oil, which have antibacterial and anti-inflammatory properties to help combat acne and improve the condition of the skin. Targeting acne aim to control sebum production, reduce inflammation, and prevent the formation of acne lesions. 3.

Hair-growth serums Minoxidil or herbal extracts that purportedly nourish hair follicles, promote circulation, and encourage healthy hair growth. Stimulate hair growth and prevent hair loss. 4. Anti-dandruff shampoos Ketoconazole, zinc pyrithione, or coal tar, which have antifungal or antibacterial properties to help control dandruff and improve scalp health.

Alleviate scalp dryness, reduce flaking, and combat the presence of dandruff-causing fungi or bacteria. 5. Sunscreens with specific claims UV filters, antioxidants, or other ingredients to shield the skin from harmful UV radiation and minimize sun damage. Offers higher sun protection factor (SPF) or additional benefits like water resistance or long-lasting protection.

COSMETICS EXCIPIENTS The substances which have no or very less therapeutic activity but are incorporated to active pharmaceutical ingredient (API), to achieve promised properties of the formulation, are called excipients. As per IPEC, “Excipients are products with insignificant or negligible effect are used to make effective formulations”. Excipients comprises of wide variety of substance with special purpose and improve the final product such as emollients, emulsifier, humactants, preservatives and thickeners et c 1 .

Ideal properties of the Cosmetic Excipients Ideal properties of cosmetic excipients are important to ensure the effectiveness, stability, and sensory claim of cosmetic formulations. 1. Compatibility with other ingredients of the formulation to prevent any adverse effect such as instability or separation. 2. It must be safe for addition in cosmetic products and should not possess any harm to the skin and hair of consumers. 3.

Excipients play an important role in maintaining the stability and shelf life of cosmetic formulations. 4. Depending upon their function, excipients should possess solubility characteristics. 5. Excipients essentially enhance texture, presentation and sensory experience. 6.

Excipients should provide a charming feel, sleekness, and attractive sensory attributes like silky touch, non-greasiness and fast absorption. 7. Ideal excipients should acquire important functional characteristics for effective intended use, thereby gives attractive resultsin the final product. 8. Excipients should be biocompatible, non-irritating, and no allergic reactions occur on the skin or hair. 9.

They should be highly favoured by a wide range of individuals with all types of skin. 10. Excipients should comply with all relevant regulatory guidelines and restrictions for cosmetic ingredients in different regions. 11. An ideal excipient can be used in various cosmetic formulations with consistent results. 12.

They should be biodegradable, sourced responsibly, and produced using sustainable practices 2 . CLASSIFICATION OF COSMETIC EXCIPIENTS C cosmetic excipients are classified into different categories given in “Figure 1: Different types of Excipients)” Cosmetic excipients Surfactants Rheology Emollients Preservatives Modifier Humectants Figure 1: Different types of Excipients Surfactants Surfactants play an important role in providing effective cleansers, shampoos and body washes. They are also known as surface-active agents as they helps to reduce the surface tension between oil and water, which is required for cleansing, luxurious foaming, and enhanced product performance.

Surfactant is an amphiphilic molecule that encompasses a hydrophilic polar head and a hydrophobic non-polar tail. The hydrophilic head group present in surfactant can be either ionic or non-ionic, whereas the hydrophobic tail is either branched or linear long-chain hydrocarbon residue with a chain length of 8-18 carbon atoms 4 . “Table 6:- [Classification of surfactants]” S. No .

Type of Surfactant Action Examples 1. Anionic surfactant Formation of cleaning, wetting, emulsifying and foaming products due to their strong detergency characteristics Fatty acid soaps, sodium lauryl sulphate, sodium laurethsulphate, ammonium lauryl sulphate, sodium cocoylisethionate, soybean phospholipids (lecithin) 2. Cationic surfactant Cationic surfactants work by electrostatically interacting with negatively charged Cetyltrimethylammonium chloride, stearalkonium surfaces, such as hair or fabric fibers. chloride, behentrimoniumchloride 3.

Non-ionic Surfactant Non-ionic surfactants are known for their mildness and compatibility with other surfactants and ingredients. Non ionic surfactants are specifically used in formulations for sensitive skin, baby care products and natural or eco-friendly formulations due to their gentle nature and biodegradability. Polysorbates, coco-glucoside, decylglucoside, lauryl glucoside 4.

Amphoteric surfactant Amphoteric surfactants, also known as zwitterionic surfactants, possess both positive and negative charges within the same molecule. Amphoteric surfactants exhibit excellent compatibility with other surfactants, good foaming properties, and mildness, making them suitable for a wide range of applications. Cocamidopropylbetaine, Disodium cocoamphodiacetate Rheology modifiers Rheological modifiers are cosmetic excipients that are used to control and alter the rheological properties in cosmetic formulations.

They helps in balancing the viscosity, flow behaviour, stability, and texture of cosmetic products, so as to ensure optimal product efficiency and consumer experience.Examples of rheology modifiers includes carbomers, cellulose derivatives, xanthan gum, acrylates copolymer, silica, polyacrylamide, hydroxypropyl guar, bentonite, Ammonium acryloyldimethyltaurate and Polyquaterniums. Carbomers : Carbomers are synthetic high molecular weight polymersacts as rheological modifierswidely used in cosmetic productssuch as creams, lotions, gels, and serums. They showeffective efficient thickeners and givesremarkably good viscosity control and gel formation abilities.

Depending upon the concentration and neutralization process, carbomers can change viscosities from low-viscosity fluids to highly viscous gels. They contribute to the stabilization of emulsions, suspension of particles, and enhancement of the product’s texture and sensory attributes. Cellulose derivatives : Cellulose derivatives like Hydroxyethyl cellulose, Hydroxypropyl methylcellulose and Sodium carboxymethyl cellulose are commonly used as rheological modifiers in cosmetic formulations.

These derivatives are procured from cellulose found in plants. They contribute to thickness, stabilization and film-forming properties to cosmetic products. They can improve the viscosity, suspension of solids, and texture of creams, lotions, and emulsions, enhancing the product’s spread ability and appearance on the skin.

Xanthan gum : It is a natural polysaccharide formed by fermentation of glucose in presence of bacteria Xanthomonascampestris . It is widely used as a rheological modifier and stabilizer in cosmetic formulations. Xanthan gum exhibits excellent thickening and suspending properties, enabling it to create gels, emulsions, and suspensions with enhanced viscosity and stability.

It helps to enhancement in texture, flow, and cling of products, providing a smooth and luxurious sensory experience. Acrylates copolymer : Acrylates copolymer is a group of polymers that are widely used as rheological modifiers in cosmetic formulations. They are producedby the polymerization reaction of acrylic acid and acrylic esters.

Acrylates copolymers provide versatile rheological properties, like thickening, stabilizing, and film forming properties. They are very frequently used in hair care products. Silica: Silica is a mineral based rheological modifier, commonly used in cosmetic formulations, such as in powders, foundations, and creams.

It is provided withdifferent particle sizes and forms, such as microspheres or colloidal silica. Silica functions as an anti-caking agent, absorbing excess oil and moisture, and imparting a soft, silky feel to the skin. It helps to enhance spread ability and blend-ability of powders.

Polyacrylamide : Polyacrylamide is a synthetic polymer used as a rheological. It can provide thickening, film-forming, and stabilizing properties. Polyacrylamide is widely present in creams, lotions, and serums, where it helps to improve viscosity, texture, and spread ability.

Hydroxypropyl guar : Hydroxypropyl guar is a modified natural polysaccharide obtained from guar gum. It is used rheological modifier in shampoos, conditioners, and body washes. Hydroxypropyl guar improves the viscosity, foam stability, and conditioning properties.

Bentonite : Bentonite is a claymineral that is used as a rheological modifier. It has improved thixotropic properties. Bentonite is frequently used in masks, creams, and cleansers.

Ammonium acryloyldimethyl taurate: This copolymer is a synthetic rheological modifier widely used in cosmetic products, such as gels and creams. It offers improved thickening, stabilizing, and emulsion stabilizing properties. Ammonium acryloyldimethyltaurate helps to enhance the texture, spread ability, and skin feel of cosmetic formulations 3 .

Polyquaterniums : Polyquaterniums are a class of polymers with cationic properties that acts as rheological modifiers in hair care formulations. They are commonly used in shampoos, conditioners, and styling products. Polyquaterniums provide conditioning, detangling, and styling benefits, while also contributing to the viscosity and flow properties of the formulations.

Humectants Humectants are cosmetic excipients helps to retain moisture in the skin or hair. They are widely employed in various cosmetic products for improvement of hydration, prevent dryness, and enhance the overall appearance of the skin or hair. There is a list of humectants used in Cosmetic and Cosmeceuticals given in Table 7:- Table 7:- List of humectants used Cosmetic and Cosmeceuticals S.

No. Name of Humectant Use 1. Glycerine It is most commonly used humectants in cosmetics.

Glycerine is versatile and found in a wide range of products such as moisturizers, lotions, creams, soaps and hair care products. 2. Hyaluronic acid Hyaluronic acid is commonly used in skin care products, particularly in serums, moisturizers, and anti-aging formulations, to improve skin hydration and reduce the appearance of fine lines and wrinkles. 3. Propylene glycol It is used in various personal care products, including creams, lotions, hair conditioners, and deodorants.

Propylene glycol also has emollient properties, contributing to the softening and smoothing of the skin. 4. Butylene glycol Butylene glycol is often found in skin care products, hair products, and cosmetics, contributing to their moisturizing and conditioning effects. 5. Panthenol Panthenol is commonly used in shampoos, conditioners, lotions, and creams, where it provides moisturization, softness, and shine to the hair and skin. 6.

Sorbitol It is widely used as a humectant in cosmetic and personal care products, including lotions, creams, and oral care products. 7. Sodium PCA Sodium PCA (pyrrolidone carboxylic acid) is a naturally occurring amino acid derivative that acts as a humectant and a skin-conditioning agent. 8. Urea Urea is a naturally occurring compound found in the skin’s natural moisturizing factor (NMF).

It is a potent humectant. 9. Polyols Polyols, such as propanediol and pentylene glycol, are versatile humectants commonly used in cosmetic formulations. 10. Saccharide isomerate Saccharide isomerate is a unique humectant derived from plant carbohydrates 11.

Honey Honey is a natural humectant that has been used for centuries in skin care products. Honey is often found in facial cleansers, masks, and moisturizers, providing moisturizing and soothing benefits. 12. Sodium hyaluronate Sodium hyaluronate is the sodium salt form of hyaluronic acid, a powerful humectant.

It has a smaller molecular size, allowing it to penetrate the skin more effectively. 13. Propanediol Propanediol is a humectant derived from corn sugar. It has a high affinity for water and helps to increase and maintain the moisture content of the skin. 14.

Betaine Betaine, also known as trimethylglycine, is a naturally derived humectant sourced from sugar beets. 15. Aloe vera gel Aloe vera gel is derived from the leaves of the aloe vera plant and is known for its hydrating and soothing properties. 16. Sorbitan isosterate Sorbitan isostearate is often found in lip balms, body butter, and makeup products.

Emollients Emollients are cosmetic ingredients that help to smooth, soften, and moisturize the skin. They form a protective barrier on the skin’s surface, preventing moisture loss and enhancing the skin’s texture and appearance. Emollients play a vital role in various skin care and personal care products, providing hydration, lubrication, and soothing properties.

Some common types of emollients used in cosmetic formulations are shown in Figure 2 4 . Figure 2 : List of emollients used in cosmetic products Preservatives Preservatives are important excipients used in cosmetic products for the prevention of microbial activity to maintain safety and stability of product. They help to increase the shelf life of cosmetic products and shield them from contamination 4 .

Some commonly used preservatives are shown in Figure 3. Figure 3: Commonly used preservatives in cosmetic products SKIN The skin also referred to as the integumentary system. It is the body's largest organ which covers the entire external surface of the body.

It measures up to 2m² and weighs around 4.5–5kg in an average adult, making up about 12–15% of total body weight. The skin serves as the primary physical barrier between the body and the external environment. It consists of three layers:

• The epidermis,
• The underlying dermis, and
• The subcutaneous tissue beneath the dermis. Each layer's anatomy, structure, and composition differ based on its specific function 5 . Structure of the skin The skin is separated into multiple layers, as shown in Figure 4. The epidermis is composed of keratinocytes. The basement membrane, sometimes referred to as the dermo-epidermal junction, is a narrow, multilayered tissue that lies beneath the epidermis and serves as an anchor between epidermis and the dermis The layer below the dermis is known as hypodermis which is made up of fat cells. Figure 4: Structure of Skin 1. Epidermis The outermost layer of the skin is epidermis which is lined by stratified squamous epithelium, is mainly made up of keratinocytes in various stages of development.

Keratinocytes are the main cells that make up the epidermis and are responsible for producing the protein keratin. The underlying dermis is completely responsible for the delivery of nutrients and the removal of waste through the basement membrane because the epidermis is avascular (has no blood vessels). The primary role of the epidermis is to serve as a biological and physical barrier that keeps allergens and irritants from penetrating the body.

At the same time, it keeps the body's internal balance and stops water loss. The epidermis is composed of layers four layers in most of cases, but those who have thickest skin have five layers 5 . The layers epidermis is:

• Stratum corneum (horny layer)
• Stratum lucidum (only found in thick skin i.e. the palms of the hands, the soles of the feet and the digits)
• Stratum granulosum (granular layer)
• Stratum spinosum (prickle cell layer)
• Stratum basale (germinative layer) Stratum corneum It is the outermost and most substantial layer of the epidermis. It is composed of 25 to 30 layers of flattened, dead skin cells called keratinocytes. These cells are packed with keratin and other proteins (with no nucleus) that create a tough, water-resistant barrier. Its slightly acidic pH, ranging from 4 to 6.5, is crucial for maintaining skin health, as changes in this pH can increase susceptibility to infections. This layer undergoes constant renewal with a complete turnover occurring roughly every four weeks. However, in older skin, this renewal process slows down and the stratum corneum tends to thicken. This thickening is thought to be a protective response to prolonged exposure to ultraviolet radiation."11

Stratum lucidum Only found in the thick skin of palms and soles, the stratum lucidum is a clear, thin layer of two to three cell layers, made so by its unique translucent keratinocytes. Stratum granulusum (granular layer) The stratum granulosum, located beneath, consists of three to five layers of granular cells derived from the spinous layer. These cells are crucial for skin barrier formation, containing either keratin-building keratohyalin granules or water-proofing lamellar granules.

The flattened cells in this layer align with the basement membrane and contribute to the final formation of the stratum corneum's keratinocytes. Stratum spinosum (prickle/spinous layer) Situated directly above the basal layer, the stratum spinosum is a relatively thick layer, composed of 8 to 10 cell layers of polyhedral keratinocytes. These cells feature outward-reaching cytoplasmic extensions, or "spines," that connect to adjacent cells via desmosomes.

The keratinocytes within this layer continue their differentiation process, ultimately contributing to the formation of the stratum corneum. Additionally, this layer contains dendritic cells. Notably, the stratum spinosum thins as a person ages 6 .

Stratum basale/stratum germinativum (basal layer) The deepest layer of the epidermis is the stratum basale, a single layer of basal cells. These cells are constantly dividing to make new skin cells. Melanocytes, which give skin its color and protect from the sun, are also found here.

The stratum basale is connected to the dermis below by the basement membrane. The basement membrane The basement membrane is a layer that separates the epidermis and dermis. It uses sticky molecules to hold them together.

As people get older, this layer thins and flattens, making the skin layers less connected 5 . 2. Dermis Located beneath the epidermis and above the subcutaneous layer, the dermis is a much thicker layer of skin, ranging from 1 to 5 millimeters. Its primary function is to provide support and sustenance to the epidermis.

The main functions of the dermis are:

• Protection
• Cushioning the deeper structures from mechanical injury;
• Providing nourishment to the epidermis;
• Playing an important role in wound healing. The dermis is divided into the superficial papillary region, composed of loose connective tissue and crucial for wound healing, and the deep reticular region, composed of dense connective tissue and providing tensile strength. The papillary region is thin and contains various cells and components, while the reticular region is thick and rich in collagen. However, with age, the dermis experiences a decline in cells responsible for extracellular matrix production and tissue remodeling. This leads to disorganized collagen and elastin deposition, ultimately resulting in a decrease in skin strength and elasticity 6 . 3. Hypodermis The hypodermis, also called the subcutaneous layer, is located beneath the dermis and connects the skin to the underlying

muscles or bones. Primarily composed of adipose tissue, it serves as a site for fat storage, cushioning, and insulation. This layer also contains a well-supplied network of blood vessels and loose connective tissue.

The flexible movement of the skin over deeper structures is attributed to the loose arrangement of collagen and elastic fibers within the hypodermis. With age, the hypodermis's ability to store fat and provide cushioning diminishes. Figure 5:Layers of Skin Functions of the skin The skin has three main functions:

• Protection
• Thermoregulation
• Sensation
• Immunological Function
• Endocrine Function Protection: The skin's primary role is to shield the body from external threats, including microorganisms and foreign substances. This protection is multifaceted, involving specialized skin cells like Langerhans cells and melanocytes, as well as circulating immune cells. However, aging diminishes the quantity and effectiveness of these cells, weakening the skin's defense system. The tough, outer layer of dead keratin and lipids provides a physical barrier, while the hypodermis offers cushioning through fat storage and glandular secretions. The skin also functions as a chemical and biological shield. Unfortunately, aging leads to a reduction in hypodermal fat and thinning of the epidermal layer, compromising these protective functions 5 . Thermoregulation: The skin is crucial for maintaining a stable body temperature

of 37°C. It achieves this through vasodilation and vasoconstriction. When the body gets cold, blood vessels in the skin narrow (vasoconstriction) to conserve heat, sweating stops, and hairs stand up to trap warm air.

Conversely, when the body gets hot, sweat glands release sweat, which cools the skin as it evaporates. Also, blood vessels widen (vasodilation) to release excess heat from the bloodstream, helping to lower the body's temperature." Sensation: The skin acts as a crucial sensory organ, enabling us to perceive and react to our surroundings. To safeguard the body from potential dangers, it possesses a sophisticated sensory system that responds to various stimuli, like the shivering response to cold.

This system is distributed throughout all three skin layers—epidermis, dermis, and hypodermis and features specialized nerve structures. Among these are Meissner corpuscles, concentrated in areas like the fingertips, which are responsible for detecting light touch. Deeper within the dermis, Vater-Pacini corpuscles, large nerve endings, enable us to perceive pressure.

Additionally, unmyelinated nerve fibers contribute to a range of sensations, including pain and temperature. This intricate network of sensory receptors allows the skin to effectively monitor and respond to the external environment 5,6 . Immunological Function: The skin plays a vital role in immunity, utilizing both innate and adaptive immune responses.

A complex communication network between skin cells, such as Langerhans cells, and immune cells regulates local immune responses. This system effectively defends the body by preventing microorganisms from entering through the skin, thus minimizing the risk of infection. Endocrine Function: The skin also functions as an endocrine organ, producing various hormones, including steroids and vitamin D.

Vitamin D synthesis occurs in the epidermal layer upon exposure to ultraviolet (UV) radiation. This vitamin is crucial for the absorption of calcium and phosphorus, essential minerals for maintaining healthy bones 6 . HAIR Human hair on the scalp is a natural product with a complex structure.

Adult hair strands are usually 20-180 µm wide and can grow up to 90 cm long. Figure 6: Structure of hair In mammals, hair serves as a multifunctional adaptation, offering thermal regulation, defense against environmental hazards like UV light and microbes, and facilitating sensory perception and social signaling. Beyond these roles, it aids in sebum and pheromone dispersal and provides camouflage 7 .

Different types of hairs Essentially, your body is covered in hair, with two main types:

• Vellus hair: This is the fine, short "peach fuzz" that covers most of your body.
• Terminal hair: This is the thicker, longer hair found on your scalp, face, and other areas like your pubic region, chest, and belly. The amount of each hair type varies based on:
• Individual differences: Everyone has a unique hair distribution.
• Age: Children primarily have vellus hair.
• Sex: Men typically have a higher percentage of terminal hair (around 90% of body surface) compared to women (around 30%). Hair Follicle Hair growth originates in the hair follicle, a tube-like structure extending from the epidermis down into the dermis. At its base, the papilla, rich in blood vessels, provides nourishment to the hair root. The germinal matrix, also located within the follicle, is where new hair cells are produced. The bulb, a rounded structure at the follicle's base, encases the papilla and germinal matrix and contains stem cells that differentiate into specialized hair cells. The growing hair is protected and shaped by inner and outer sheaths lining the follicle. The inner sheath terminates near the sebaceous gland, while the

outer sheath extends to it. The sebaceous gland releases sebum, a natural oil that conditions the hair and skin. Sebum production increases during puberty, contributing to acne, and decreases with age, leading to dry skin.

The arrector pili muscle, attached to the outer sheath, contracts to make hair stand up, creating goose bumps." Hair Shaft The hair shaft is the part of the hair that we can see. Once the hair grows beyond the skin’s surface, the cells aren’t alive anymore. It’s made up of three layers of keratin, a hardening protein.

Layers of the Hair Shaft: 1. Medulla (Inner Layer):

• This innermost layer isn't always present. It varies with hair type.
• The medulla is the innermost layer which is found primarily in thicker hair.
• It's a soft, thin core of transparent cells and air spaces. 2. Cortex (Middle Layer):
• The cortex constitutes the majority of the hair shaft.
• It houses pigment cells for determining hair color.
• The cortex along with the medulla contains pigment cells.
• The cortex forms the bulk of the hair and contains its color.
• It consists of keratin filaments held together by disulfide and hydrogen bonds.
• The cortex's health relies on the cuticle's integrity. 3. Cuticle (Outer Layer):
• The cuticle is the outermost layer that composed of overlapping scales resembling roof shingles.
• Hair conditioning products often target the cuticle, aiming to smooth its structure.
• The cuticle serves as the hair's protective barrier with overlapping cells resembling scales.
• A healthy cuticle is smooth and flat, providing shine and protecting inner layers.
• It regulates moisture balance and flexibility.
• Chemical treatments and environmental exposure can damage the cuticle, leading to dryness and brittleness 8 . Hair Growth Cycle Scalp hair grows at a rate of less than half a millimeter daily. Each individual hair follicle cycles through three distinct phases: Anagen (active growth), Catagen (transition) and Telogen (resting) as shown in fig. Each phase has a distinct duration and characteristics, and the cycle repeats throughout a person's life 7 . Figure 7: Hair Growth Cycle Anagen (Growth Phase):
• This is the active growth period, lasting several years for scalp hair.
• New hair pushes out older and non-growing hairs.
• This phase is much shorter for eyelashes, eyebrows and body hair i.e. around 30-45 days, limiting their length 8 . Catagen (Transition Phase):
• This is a brief transitional phase, lasting a few weeks with about 2% of scalp hairs in this stage at any time.
• Hair growth slows and the outer root sheath shrinks and attaches to the hair root, forming a "club hair" that has stopped growing. Telogen (Resting Phase):
• This is the resting phase, lasting approximately three months and accounts for 10-15% of scalp hair.
• The hair follicle is inactive and the club hair is fully formed.
• Pulling a telogen hair reveals a dry and white substance at the root 8 . ORAL CAVITY The oral cavity stretches from the lips at its front to the pharynx at its rear. The boundary between the oral cavity and the pharynx is defined by the palatoglossal folds, which occur in pairs. These folds create the oropharyngeal isthmus, essentially the doorway leading into the pharynx. The oral cavity stretches from the opening between the lips, known as the oral fissure and It ends at the entrance to the throat, known as oropharyngeal isthmus. The upper and lower dental arches, formed by the teeth and their supporting bone 9 . The oral cavity divided into two main areas:
• The vestibule: The space between the cheeks/lips and the teeth.
• The oral cavity proper: The space within the dental arches, containing the tongue. The vestibule is a narrow, slit-like space in the mouth. It is located between the lips and cheeks on the outside and the gums and teeth on the inside. It opens to the outside through the space between the lips and connects to the main part of the mouth behind the last molar teeth when the jaws are closed. The upper and lower limits of the vestibule are where the mucous membrane folds from the lips and cheeks onto the gums. The outer wall of the vestibule is formed by the cheek, which consists of the buccinator muscle covered by mucous membrane. The labial frenum (a small

fold of tissue) connects each lip to the gum ridge; the upper frenum is usually larger 10 . A bulge above the upper canine tooth, the canine eminence, extends into the vestibule and a shallow depression next to it is called the canine fossa. The parotid salivary gland's duct empties saliva into the vestibule through a small opening opposite the upper second molar tooth.

Figure 8: The two divisions of the oral cavity are the vestibule and oral cavity proper The mouth proper lies posteriorly to the vestibule. It is bordered by a roof, a floor, and the cheeks. The tongue fills a large proportion of the cavity of the mouth proper as shown in figure...

Roof of the Mouth: The roof is composed of the hard and soft palates. Hard Palate: This is the front portion, a bony plate separating the nasal and oral cavities. It's covered with different types of mucous membrane: respiratory mucosa on the nasal side, and oral mucosa on the mouth side 11 .

Soft Palate: This is the back portion, an extension of the hard palate but made up of muscle. It acts like a valve, moving to close off the entrance to the throat (oropharyngeal isthmus) or to separate the nasal part of the throat (nasopharynx) from the oral part (oropharynx). The cheeks are primarily composed of the buccinator muscle, which is covered on the inside by oral mucous membrane.

The buccinator muscle plays a key role in chewing by keeping food positioned between the teeth. This muscle receives its nerve supply from the buccal branches of the facial nerve (cranial nerve VII). Floor The floor of the mouth is made up of several important components:

• Muscular diaphragm: This is formed by the paired mylohyoid muscles. It provides structural support to the floor of the mouth and helps move the larynx forward when swallowing.
• Geniohyoid muscles: These muscles also assist in pulling the larynx forward during swallowing.
• Tongue: The tongue is connected to the floor of the mouth by the frenulum, a fold of mucous membrane 12 . The tongue is a muscular organ located in the oral cavity, playing crucial roles in taste, speech, and digestion. Here's a breakdown of its key features: Structure and Anatomy of Tongue 1. Muscles: The tongue is composed of both intrinsic and extrinsic muscles: Intrinsic muscles: These muscles are located entirely within the tongue and are responsible for changing its shape. Extrinsic muscles: These muscles originate outside the tongue and insert into it, controlling its position and movement. 2. Papillae: The tongue's surface is covered with small projections called papillae, which contain taste buds. There are four main types: Filiform

papillae: The most numerous, giving the tongue its rough texture. They don't contain taste buds. Fungiform papillae: Mushroom-shaped, located primarily on the tip and sides of the tongue.

They contain taste buds. Circumvallate papillae: Large, dome-shaped, located at the back of the tongue. They contain many taste buds.

Foliate papillae: Located on the lateral edges of the tongue. They also contain taste buds. Frenulum: A fold of mucous membrane, the lingual frenulum, connects the underside of the tongue to the floor of the mouth 13 . 3.

Blood supply and nerves: The tongue has a rich blood supply and is innervated by several cranial nerves, including those responsible for taste and movement. Figure 9: Structure of Tongue Functions:

• Taste: Taste buds on the papillae detect different tastes (sweet, sour, salty, bitter, and umami).
• Speech: The tongue's precise movements are essential for articulating words.
• Digestion: The tongue aids in chewing by manipulating food and forming a bolus for swallowing.
• Swallowing: The tongue plays a vital role in initiating the swallowing reflex.
• Oral hygiene: The movement of the tounge helps to clean the oral cavity.
• Salivary glands and their ducts: These glands release saliva into the floor of the mouth. Salivary glands are exocrine glands (Parotid Glands, Submandibular Glands and Sublingual Glands) that produce saliva, which plays a vital role in oral health and digestion 14. Minor Salivary Glands: In addition to the major glands, there are numerous minor salivary glands scattered throughout the oral mucosa, including: Labial glands (in the lips), Buccal glands (in the cheeks), Palatal glands (in the palate) and Lingual glands (in the tongue).These minor glands primarily produce mucous saliva and contribute to the overall moisture of the oral cavity. Teeth Teeth are hard, calcified structures found in the jaws of vertebrates and they play a vital role in several functions

such as: Mechanical Digestion: Teeth break down food into smaller pieces and make it easier to swallow and digest. Speech: They contribute to the articulation of sounds and aiding in clear speech. Aesthetics: Teeth play a significant role in facial appearance and contribute to self-confidence 15 .

Types of Teeth: There are four main types of teeth

• Incisors: These are the sharp, front teeth used for cutting food.
• Canines: These are pointed teeth used for tearing food.
• Premolars: These teeth, located behind the canines, are used for crushing and grinding food.
• Molars: These are the large, flat teeth at the back of the mouth and used for grinding food. Tooth Structure: A tooth is composed of several layers as shown in figure:
• Enamel: It is hard and outer layer that protects the tooth. It's the hardest substance in the human body 16 .
• Dentin: The layer beneath the enamel, which is softer and contains tiny tubules.
• Pulp: The innermost layer, containing nerves, blood vessels and connective tissue.
• Cementum: A layer that covers the tooth root and helps to anchor the tooth to the jaw. Figure 10: Anatomy of Teeth Dental Health: Maintaining good oral hygiene is crucial for healthy teeth. This includes:
• Brushing: Brushing teeth twice daily with fluoride toothpaste.
• Flossing: Flossing daily to remove plaque and food particles from between teeth.
• Regular Dental Checkups: Visiting a dentist for professional cleanings and examinations.
• Diet: Limiting sugary foods and drinks 17 . Common Problems Associated with Teeth and Gums Various dental issues, such as cavities, tooth erosion, and gum infections or diseases, can lead to pain and discomfort. These problems can also interfere with eating and negatively affect a person's confidence. Globally, the World Health Organization recognizes dental diseases as some of the most prevalent long-term health conditions 17 . General symptoms Symptoms can vary depending on the cause. However, a common symptom of dental problems includes:
• Toothache
• Sensitivity to cold or hot food or drinks
• Loose teeth
• Sudden pain while eating cold or sweet foods
• Tooth changing color or shape
• Worn teeth, including holes, cracks, or chips on the tooth
• Bleeding or swollen gums
• Gum pain
• Swollen cheeks
• Clicking jaw Dental caries: It is commonly known as cavities, occur when plaque, a sticky film of bacteria, accumulates on tooth surfaces. This plaque then metabolizes free sugars found in foods and drinks (including added sugars and naturally occurring sugars in items like honey and fruit juices) into acids. Over time, these acids erode the tooth enamel, leading to decay 14 Several factors contribute to the development of dental caries:
• Plaque Formation: The initial buildup of bacteria on teeth.
• High Free Sugar Intake: Consuming excessive amounts of sugars provides fuel for the bacteria in plaque.
• Inadequate Fluoride Exposure: Fluoride strengthens tooth enamel and helps prevent acid damage.
• Insufficient Plaque Removal: Ineffective or infrequent tooth brushing allows plaque to accumulate. Dental caries can be the result of: Tooth destruction Pain and discomfort Tooth loss Infections Periodontal disease: It is also known as gum disease, impacts the tissues that surround and support teeth. Symptoms include bleeding or swollen gums (gingivitis), pain, and occasionally bad breath. In advanced cases, the gums can recede from the teeth and supporting bone, leading to loose teeth and potential tooth loss. It's estimated that severe periodontal disease affects approximately 19% of adults globally, exceeding one billion cases. The primary causes of this condition are inadequate oral hygiene and tobacco use 15 . Edentulism (complete tooth loss): Edentulism or complete tooth loss, typically results from

a long-term history of oral health problems, primarily advanced cavities and severe gum disease. It can also be caused by injuries or other factors. Globally, about 7% of adults aged 20 and older experience total tooth loss.

This number significantly increases to approximately 23% among individuals aged 60 and above. Losing all your teeth can have significant psychological, social, and functional consequences 18 . Tartar: Dental calculus, also called Tartar, is hardened plaque that forms on teeth.

It's a significant factor in the development and progression of gum disease. Rough root surfaces promote the buildup and adherence of calculus. While the rough calculus itself might not directly cause gum inflammation, it creates an ideal surface for bacteria to thrive below the gum line.

Treatment for calculus-related infections focuses on removing the bacterial biofilm and hardened deposits from the affected root surfaces through a procedure called root debridement. Periodontitis: It is an inflammatory condition affecting the tissues that support the teeth. It's caused by specific bacteria, leading to the gradual breakdown of the periodontal ligament (which connects the tooth to the bone) and the alveolar bone (which supports the teeth).

This destruction results in the formation of periodontal pockets (spaces between the teeth and gums) and/or gum recession (where the gums pull away from the teeth) 19 . The term "periodontium" originates from Greek words meaning "around" and "tooth," indicating the tissues surrounding and supporting the teeth" 16 . Tooth decay: Tooth decay, also known as cavities or caries, is the breakdown of teeth due to acids produced by bacteria.

The cavities may be a number of different colors from yellow to black. Symptoms may include pain and difficulty with eating. Chipped Teeth: Tooth enamel is one of the hardest substances in the human body, it's not indestructible.

Strong impacts or prolonged wear can cause teeth to chip, resulting in a tooth with a rough, uneven edge and potentially affecting appearance. Oral Cancer: Oral cancer is also known as mouth cancer. It is a type of head and neck cancer that develops in any part of the oral cavity (mouth).

It can occur on the lips, tongue, gums, cheeks, the floor of the mouth, and the hard and soft palate. Most oral cancers are squamous cell carcinomas, which originate in the cells that line the mouth and throat. Excessive alcohol consumption, use of tobacco, Human papillomavirus (HPV) infection, sun exposure, Weak immune system, poor nutrition, age, gender are the main causes for oral cancer 19.

CONCLUSION It has been concluded from the aforementioned chapter that cosmetic find a new way in the treatment of some ailments along with its basic property to enhance everybody’s appearance. Use of the different excipients incorporation in the cosmetic formulations gives good nourishing and moisturizing properties along with mechanism of action behind it. This chapter gives an insight about the skin and hair structure and function which will gives you an idea about penetrability of cosmetic through skin and hair.

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