What Are Anhydrous Formulations?

Anhydrous formulations are cosmetic products that contain no intentionally added water. They are generally based on oils, esters, waxes, butters, silicones or other non-aqueous materials.

Common examples include lip balms, lipsticks, facial oils, cleansing oils, body balms, petroleum-based products and certain solid sticks.

Cosmetic Uses of Anhydrous Formulations

Anhydrous systems are particularly useful when a product is designed around oil-soluble ingredients or when a water-free texture is desired. They can also be advantageous for ingredients that are unstable in aqueous environments.

The absence of water can reduce the conditions required for microbial growth. However, an anhydrous product is not automatically microbiologically safe. Water can be introduced during consumer use, particularly in products handled with wet hands or used in the shower.

Stability Considerations

Oxidative stability is often an important consideration in anhydrous formulations. Oils containing high levels of unsaturated fatty acids can oxidise during storage, potentially causing changes in odour, colour and sensory properties.

Antioxidants, oxygen-limiting packaging and appropriate storage conditions may therefore be important for maintaining product stability.

Texture and Processing

In balms and sticks, the selection of waxes and their crystallisation behaviour strongly influences hardness, payoff, melting point and sensory properties.

Cooling conditions can also affect crystal formation and therefore the final texture of the product. Processing temperature and cooling rate should be controlled during development and scale-up.

References

Barel, A. O., Paye, M. and Maibach, H. I. Handbook of Cosmetic Science and Technology. CRC Press.

European Commission. CosIng – Cosmetic Ingredients Database.

What Is the Aqueous Phase?

The aqueous phase is the water-rich part of a cosmetic formulation. In conventional emulsions, it is combined with an oil phase to produce the final emulsion.

Purified water is usually its major component, but the aqueous phase may also contain glycerin, propanediol, glycols, water-soluble polymers, acids, bases, buffers, chelating agents, preservatives and water-soluble active ingredients.

Role of the Aqueous Phase in Formulation

The composition of the aqueous phase has a major influence on the properties of the finished product. Factors such as pH, conductivity, ionic strength and dissolved solids can affect viscosity, emulsification, preservation and ingredient stability.

The order in which ingredients are added can also be important. Some polymers need to be fully hydrated before electrolytes are introduced, while heat-sensitive active ingredients may need to be incorporated during the cooling phase.

Formulation Considerations

Water quality is critical in cosmetic manufacturing. Variations in mineral content, microbial quality and conductivity can contribute to differences between production batches.

The aqueous phase should be evaluated for pH, clarity, viscosity and compatibility before and after incorporation into the complete formulation. An ingredient that performs well in water alone may behave differently once combined with the other components of the finished product.

References

Barel, A. O., Paye, M. and Maibach, H. I. Handbook of Cosmetic Science and Technology. CRC Press.

European Commission. CosIng – Cosmetic Ingredients Database.

Lachman, L., Lieberman, H. A. and Kanig, J. L. The Theory and Practice of Industrial Pharmacy.

What Is an Active Ingredient?

An active ingredient is an ingredient selected because it is intended to provide a defined cosmetic effect in the finished product. Examples include ingredients used to moisturise the skin, reduce the appearance of wrinkles, improve skin texture, provide antioxidant protection, condition hair or support an even-looking complexion.

The term “active ingredient” is widely used in cosmetic formulation and marketing, but its precise regulatory meaning depends on the market. An ingredient described as an active in cosmetic development should not automatically be considered a medicinal active ingredient.

Concentration and Formulation

The concentration of an active ingredient is an important consideration. The concentration required for formulation performance may be different from the concentration used to support a particular cosmetic claim.

An active ingredient should be evaluated for:

• Solubility
• Stability
• Compatibility
• pH sensitivity
• Temperature sensitivity
• Interaction with other formulation components

Some actives are sensitive to oxygen, light or heat and may require specific processing conditions or protective packaging. Others may require encapsulation or a particular delivery system.

The supplier specification should also be reviewed carefully, as the same INCI ingredient can be supplied in different grades, concentrations or delivery systems.

Cosmetic Claims and Efficacy

When an active ingredient is used to support a cosmetic claim, the evidence should be appropriate to the claim being made.

Ingredient literature can provide useful background information, but evidence relating to an isolated ingredient does not automatically demonstrate the efficacy of the finished cosmetic product. Where appropriate, finished-product testing can provide stronger support for cosmetic claims.

Ingredient Information

Ingredient Type: Functional cosmetic ingredient
CAS / EINECS/EC: Not applicable to the general term “active ingredient.”

References

Barel, A. O., Paye, M. and Maibach, H. I. Handbook of Cosmetic Science and Technology. CRC Press.

European Commission. CosIng – Cosmetic Ingredients Database.

European Commission. Commission Regulation (EU) No 655/2013.

What Is Phenethyl Alcohol?

Phenethyl alcohol, also known as phenylethyl alcohol or 2-phenylethanol, is an aromatic alcohol with a characteristic soft, sweet, rose-like odour. It occurs naturally in rose oil and various other natural materials, although commercial cosmetic-grade phenethyl alcohol is commonly produced synthetically.

Cosmetic Uses of Phenethyl Alcohol

Phenethyl alcohol is widely used in cosmetic and personal care products as a fragrance ingredient and masking agent. Its pleasant floral character makes it particularly useful in perfumes and fragranced skin and hair care products.

It is also used as part of cosmetic preservation systems because of its antimicrobial activity. However, it should not automatically be considered a complete broad-spectrum preservative when used alone. Its effectiveness depends on the concentration, formulation pH, water activity, packaging and other components of the preservation system.

Phenethyl alcohol can be found in:

• Skin care products
• Hair care products
• Cleansers
• Creams and lotions
• Fragrances
• Deodorants

Formulation Considerations

The concentration should be selected according to the intended function. A concentration selected primarily for fragrance may not provide sufficient antimicrobial protection, while a concentration selected for antimicrobial activity can significantly influence the sensory profile of the finished product.

Compatibility with other fragrance materials, preservatives, emulsifiers and active ingredients should be evaluated during formulation development.

Safety

The Cosmetic Ingredient Review Expert Panel concluded that phenethyl alcohol is safe for use in cosmetics and personal care products at concentrations of up to 1%. The appropriate concentration in a finished product should nevertheless be determined according to product type, exposure conditions and applicable regulations.

Ingredient Information

INCI: Phenethyl Alcohol
Other Names: Phenylethyl Alcohol, 2-Phenylethanol
CAS: 60-12-8
EINECS/EC: 200-456-2
Molecular Formula: C₈H₁₀O
Molecular Weight: 122.17 g/mol
Chemical Class: Aromatic Alcohol
Functions: Fragrance Ingredient, Preservative-supporting Ingredient, Masking Agent

References

Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

Cosmetic Ingredient Review Expert Panel. Final Report on the Safety Assessment of Phenethyl Alcohol.

Cosmetic Ingredient Review Expert Panel. Annual Review of Cosmetic Ingredient Safety Assessments, 2006.

U.S. Food and Drug Administration. Food Additive Status List – Phenethyl Alcohol.

European Commission. CosIng – Cosmetic Ingredients Database.

National Center for Biotechnology Information. PubChem – Phenethyl Alcohol.

National Center for Biotechnology Information. PubMed – Phenethyl Alcohol safety and toxicology.

What Is Glutamic Acid?

Glutamic acid is a naturally occurring acidic amino acid that forms part of proteins and peptides. It is also an important component of the amino acid pool present in the skin's Natural Moisturizing Factor (NMF).

As an amino acid with two carboxylic acid groups and one amino group, its ionic state and behaviour in cosmetic formulations depend on pH.

Cosmetic Uses of Glutamic Acid

Glutamic acid and glutamate-derived ingredients are used in a wide range of cosmetic and personal care products, including skin care, hair care, bath products, eye makeup and tanning products.

Its main cosmetic relevance is its ability to contribute to water binding and skin conditioning. It can therefore be incorporated into moisturising formulations and amino-acid-based systems designed to complement components of the skin's NMF.

Hair Care

Glutamic acid can also be used in hair care formulations. Amino acids may contribute to hair conditioning and help improve the feel, flexibility and manageability of the hair.

Glutamic acid may be incorporated into moisturising systems designed to support hair hydration and conditioning.

Glutamic Acid Derivatives

Glutamic acid should not be confused with related ingredients such as Sodium Glutamate, Zinc Glutamate, Polyglutamic Acid and Sodium Polyglutamate. Although chemically related, these materials have different molecular structures, physicochemical properties and formulation behaviour.

Formulation Considerations

Glutamic acid is water soluble and is generally suitable for incorporation into the aqueous phase of cosmetic formulations. Because it is ionisable, formulation pH can influence its behaviour.

Compatibility with preservatives, electrolytes and other active ingredients should be evaluated during formulation development. Finished products should also undergo appropriate stability testing.

Ingredient Information

INCI: Glutamic Acid
CAS: 56-86-0
EINECS/EC: 200-293-7
Molecular Formula: C₅H₉NO₄
Molecular Weight: 147.13 g/mol
Chemical Class: Amino Acid
Functions: Humectant, Antistatic, Skin Conditioning Agent

References

Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

U.S. Food and Drug Administration. Substances Generally Recognized as Safe (GRAS).

European Commission. CosIng – Cosmetic Ingredients Database.

National Center for Biotechnology Information. PubChem – Glutamic Acid.

National Center for Biotechnology Information. PubMed – Glutamic Acid, Natural Moisturizing Factor and skin hydration.

Ashland. Hygroplex™ HHG – Technical Information.

What Is Grapefruit Peel Oil?

Citrus paradisi (grapefruit) peel oil is a volatile aromatic oil obtained from the outer peel of grapefruit, primarily by cold expression or cold pressing.

The oil contains a complex mixture of volatile compounds, with limonene typically being the predominant constituent. Other components include α-pinene, sabinene, myrcene, geraniol, linalool and other aromatic compounds.

Cosmetic Uses of Grapefruit Peel Oil

Grapefruit peel oil is primarily used as a fragrance ingredient and masking agent. Its fresh, bright citrus aroma makes it suitable for a wide range of fragranced cosmetic and personal care products, including:

• Creams and lotions
• Cleansers and body washes
• Shampoos and conditioners
• Soaps
• Deodorants
• Other fragranced skin and hair care products

It can also be combined with floral, woody, herbal, green and other citrus oils to create more complex fragrance profiles.

Phototoxicity and Formulation Considerations

Particular care is required when using grapefruit peel oil in products applied to skin that may subsequently be exposed to sunlight. The phototoxic potential of citrus oils depends on the extraction method and the concentration of naturally occurring furanocoumarins and other photoreactive compounds.

The use level should therefore be assessed according to the specific raw material, product category, current IFRA Standards and applicable regulatory requirements. The supplier's current IFRA certificate and allergen declaration should be obtained before formulation.

Grapefruit peel oil is also susceptible to oxidation. Heat, light and oxygen can alter its composition and odour profile and may increase the sensitisation potential of oxidation products. Appropriate storage and stability testing are therefore important.

Ingredient Information

INCI: Citrus Paradisi Peel Oil
CAS: 8016-20-4
EINECS/EC: Not specified
Functions: Fragrance Ingredient, Masking Agent

References

Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

International Fragrance Association (IFRA). IFRA Standards and Guidance for Fragrance Ingredients.

European Commission. CosIng – Cosmetic Ingredients Database.

National Center for Biotechnology Information. PubChem – Citrus paradisi and grapefruit peel oil constituents.

National Center for Biotechnology Information. PubMed – Citrus essential oils, phototoxicity and safety.

Food and Drug Administration. 21 CFR – Flavoring substances and related regulatory information.

What Is Juniperus Communis Fruit Extract?

Juniperus communis fruit extract is obtained from the ripe fruits of Juniperus communis L., commonly known as common juniper or juniper berry. The fruits can be extracted using different methods, including water and ethanol, producing extracts with different chemical compositions.

Cosmetic Uses of Juniper Fruit Extract

Juniper fruit extract is primarily used as a skin-conditioning and antioxidant botanical ingredient. Depending on its composition, it may also contribute astringent, antimicrobial and sensory properties to cosmetic formulations.

It can be incorporated into creams, lotions, gels, serums and other skin care products. Juniper-derived ingredients are also used in colour cosmetics, including lipsticks, foundations, mascaras, blushers and face powders.

Antioxidant Properties

Water and ethanol extracts of Juniperus communis fruits have demonstrated antioxidant activity in laboratory studies. This activity is associated with naturally occurring phenolic compounds and other phytochemicals.

However, in-vitro antioxidant activity should not automatically be interpreted as a clinically demonstrated antioxidant effect on human skin. The composition and performance of the extract depend strongly on the extraction method, geographical origin, fruit maturity and processing conditions.

Formulation Considerations

Water-based extracts can generally be incorporated into the aqueous phase of emulsions, gels and lotions, while ethanol-based extracts may require different handling.

The colour, odour and composition of botanical extracts can vary between suppliers and batches. Compatibility with preservatives, pH, electrolytes and other formulation components should be evaluated during development.

Ingredient Information

INCI: Juniperus Communis Fruit Extract
Botanical Name: Juniperus communis L.
Plant Part Used: Ripe fruit
Family: Cupressaceae
CAS / EINECS/EC: Not specified on the original page
Functions: Skin Conditioning, Antioxidant

References

Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

Cosmetic Ingredient Review Expert Panel. Safety Assessment of Juniper-Derived Ingredients as Used in Cosmetics.

European Commission. CosIng – Cosmetic Ingredients Database.

National Center for Biotechnology Information. PubChem – Juniperus communis.

National Center for Biotechnology Information. PubMed – Juniperus communis fruit antioxidant activity.

U.S. Food and Drug Administration. GRAS Substances Database – Juniper Berry Oil.

Kováts, E. and others. Research concerning the phytochemical composition and biological activity of Juniperus communis fruit extracts.

What Is Lawsone?

Lawsone is the principal colouring molecule found in the leaves of Lawsonia inermis, commonly known as henna. Chemically, it is 2-hydroxy-1,4-naphthoquinone, a naturally occurring naphthoquinone responsible for henna's characteristic orange-red to reddish-brown colour.

Cosmetic Uses of Lawsone

Lawsone is primarily used as a natural colorant and hair-colouring agent. It has a strong affinity for keratin, allowing it to interact with keratin proteins and produce a durable colour on the hair.

Henna preparations can produce warm orange, copper, auburn or reddish-brown shades. The final colour depends on the natural hair colour, concentration and quality of lawsone, application conditions and the presence of other botanical colourants.

Lawsone is also responsible for the traditional use of henna in temporary decorative skin staining. The pigment interacts with keratin in the superficial layers of the skin, producing a stain that gradually fades as the outer skin cells are shed.

Formulation Considerations

Lawsone can be delivered through henna leaf preparations or suitable extracts. The concentration of available pigment, botanical source, harvesting, processing and storage conditions can all influence colouring performance.

pH and application conditions may also affect the release and interaction of lawsone with keratin. Finished products should undergo appropriate stability testing, particularly for changes in colour and colouring performance.

Safety Considerations

Pure, uncontaminated henna has traditionally been used for cosmetic colouring, but allergic contact dermatitis has been reported. Particular care should be taken with products marketed as “black henna,” which may contain para-phenylenediamine (PPD) or other added colourants that are not naturally present in pure henna.

Ingredient Information

INCI: Lawsonia Inermis Leaf Extract
Chemical Name: 2-Hydroxy-1,4-naphthoquinone
CAS: 83-72-7
Chemical Class: Naphthoquinone
Molecular Formula: C₁₀H₆O₃
Molecular Weight: 174.15 g/mol

The exact INCI designation should be confirmed against the raw material specification, particularly when using an isolated lawsone preparation rather than a whole henna leaf extract.

References

Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

European Commission. CosIng – Cosmetic Ingredients Database.

National Center for Biotechnology Information. PubChem – Lawsone.

National Center for Biotechnology Information. PubMed – Lawsonia inermis and lawsone.

World Health Organization. WHO Monographs on Selected Medicinal Plants – Lawsonia inermis.

Semwal, R. B., Semwal, D. K., Combrinck, S., and Viljoen, A. M. “Lawsonia inermis L. (henna): Ethnobotanical, phytochemical and pharmacological aspects.” Journal of Ethnopharmacology.

Al-Snafi, A. E. “A review on Lawsonia inermis: A potential medicinal plant.” International Journal of Current Pharmaceutical Research.

What Is Juglans Nigra?

Juglans nigra, commonly known as black walnut, is a deciduous tree native to eastern and central North America. Different parts of the plant—including the bark, leaves, green fruit hulls and mature seeds—have different chemical compositions and should be considered as distinct cosmetic raw materials.

Cosmetic Uses of Juglans Nigra

Black walnut seed oil can function as a plant-derived emollient and skin-conditioning ingredient. It can be incorporated into creams, lotions, balms, facial oils and other oil-based formulations.

Extracts from the leaves, bark and green hulls contain tannins, phenolic compounds and other constituents that may contribute to astringent and antioxidant properties. Green walnut hulls have traditionally been used in skin cleansing and colouring preparations.

The traditional topical uses of black walnut should be distinguished from scientifically demonstrated cosmetic benefits. Properties observed in concentrated extracts should not automatically be attributed to black walnut seed oil.

Formulation Considerations

The appropriate formulation approach depends on the specific plant part and extraction method. Seed oil can be incorporated into the oil phase of emulsions or used in anhydrous products, while extracts may require different solvent systems.

Hull and bark extracts can contain strongly coloured constituents that may affect the colour and stability of the finished product. Seed oil may also require protection against oxidation due to its unsaturated fatty acids.

Safety and Regulatory Considerations

The safety profile of black walnut seed oil should not be inferred from toxicological data relating to bark, hull or leaf extracts. Concentrated extracts should be evaluated according to their composition, concentration, purity and intended exposure.

The exact botanical identity, plant part, INCI designation, extraction method and supplier specification should be confirmed during cosmetic product development.

References

Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

European Medicines Agency. Juglans regia L., folium – European Union herbal monograph.

National Center for Biotechnology Information. PubChem – Juglone.

National Center for Biotechnology Information. PubMed – Juglans nigra and juglone.

European Commission. CosIng – Cosmetic Ingredients Database.

U.S. Department of Agriculture. Juglans nigra L. – Black Walnut.

Bhatia, K. et al. Research on the phytochemistry and biological activities of Juglans nigra and its constituent juglone.

What Is Coriandrum Sativum Seed Oil?

Coriander seed oil is the fixed oil obtained from the seeds of Coriandrum sativum L., commonly known as coriander. The oil has a distinctive fatty acid profile, with petroselinic acid often representing around 60–75% of its fatty acids.

It should be distinguished from coriander essential oil, which is a volatile aromatic fraction with a substantially different composition.

Cosmetic Uses of Coriander Seed Oil

Coriander seed oil is primarily used as an emollient and skin-conditioning ingredient. It can be incorporated into creams, lotions, balms, facial oils and cleansing products, as well as hair care formulations.

Its lipid composition provides a conditioning and lubricating effect that can help leave the skin feeling softer and smoother. The presence of linoleic acid is also relevant to formulations supporting the skin barrier.

Formulation Considerations

Coriander seed oil can be incorporated into the oil phase of emulsions or used directly in anhydrous formulations. It can be combined with other vegetable oils, esters, butters and synthetic emollients to modify the sensory properties and fatty acid profile of a formulation.

The stability and sensory characteristics of the oil can vary depending on its origin, processing, refining and fatty acid composition. Finished formulations should therefore undergo appropriate stability testing.

Ingredient Information

INCI: Coriandrum Sativum Seed Oil
Plant Part Used: Seed
Country of Origin: Ukraine
Functions: Skin Conditioning, Emollient

CAS / EINECS/EC: Not specified on the original page.

References

Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

Senrayan, J. and Venkatachalam, S. “Optimization of ultrasound-assisted solvent extraction (UASE) based on oil yield, antioxidant activity and evaluation of fatty acid composition and thermal stability of Coriandrum sativum L. seed oil.” Journal of Food Science and Technology, 2019. DOI: 10.1007/s10068-018-0467-1.

“Effect of the supplementation of virgin coriander seed oil on reducing reactivity in healthy women with sensitive skin: a randomized double-blind placebo-controlled pilot clinical study.” Clinical, Cosmetic and Investigational Dermatology, 2022.

“Coriandrum sativum L.: A Review on Ethnopharmacology, Phytochemistry, and Cardiovascular Benefits.” Molecules, 2021.

“Essential Oil from Coriandrum sativum: A review on Its Phytochemistry and Biological Activity.” Molecules, 2023.

Burdock, G. A. and Carabin, I. G. “Safety assessment of coriander (Coriandrum sativum L.) essential oil as a food ingredient.” Food and Chemical Toxicology, 2009, 47(1), 22–34. DOI: 10.1016/j.fct.2008.11.006.

What Is Camellia Japonica Seed Oil?

Camellia japonica seed oil, also known as Tsubaki oil or Japanese camellia seed oil, is the fixed oil expressed from the seeds of Camellia japonica. It has a long history of use in Japanese skin and hair care.

The oil is predominantly composed of triglycerides, with oleic acid typically accounting for around 80% of its fatty acid composition.

Cosmetic Uses of Camellia Japonica Seed Oil

Camellia japonica seed oil is primarily used as an emollient and skin-conditioning ingredient. Its high oleic acid content gives formulations a smooth, lubricating and relatively rich skin feel.

It can be incorporated into:

• Facial oils and creams
• Cleansing oils
• Lotions and balms
• Hair oils
• Conditioners and hair masks
• Leave-in hair treatments

In hair care, Tsubaki oil is traditionally used to condition the hair and improve its softness, smoothness and manageability.

Formulation Considerations

Camellia japonica seed oil is oil-soluble and can be incorporated directly into the oil phase of anhydrous products and emulsions. Its oxidative stability should still be considered because, although it is rich in oleic acid, it also contains smaller amounts of polyunsaturated fatty acids.

The botanical identity should be confirmed carefully, as Camellia japonica and Camellia sinensis are different species.

Ingredient Information

INCI: Camellia Japonica Seed Oil
Function: Emollient, Skin Conditioning

CAS / EINECS/EC: Not specified on the original page.

References

Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

National Center for Biotechnology Information. PubChem – Camellia japonica and related constituents.

European Commission. CosIng – Cosmetic Ingredients Database.

Lee, et al. Research investigating the anti-inflammatory activity of Camellia japonica oil through NF-κB and AP-1 signaling pathways.

Matsui, et al. Research on the fatty acid composition and physicochemical properties of Camellia seed oils.

What Is Tranexamic Acid?

Tranexamic acid is a synthetic derivative of the amino acid lysine. It is a white crystalline, water-soluble compound that has been investigated for topical cosmetic applications, particularly in formulations targeting pigmentation concerns.

Cosmetic Uses of Tranexamic Acid

Tranexamic acid is increasingly used in skin care products designed to improve the appearance of uneven skin tone and hyperpigmentation. It is particularly associated with products targeting the appearance of melasma and post-inflammatory hyperpigmentation.

It can be incorporated into serums, creams, lotions and other leave-on skin care products. Clinical research has investigated topical formulations containing concentrations including 2% and 5%, although the appropriate concentration depends on the formulation, intended use and applicable regulatory requirements.

Formulation Considerations

Tranexamic acid is water soluble, making it suitable for aqueous systems such as serums, gels and emulsions. During formulation development, pH, preservatives, other active ingredients and packaging should be considered when assessing compatibility and stability.

The finished formulation should undergo appropriate stability and skin-tolerability testing. Combining tranexamic acid with other ingredients targeting uneven pigmentation may require particular attention to formulation pH and irritation potential.

Regulatory Considerations

Tranexamic acid is primarily recognised as a pharmaceutical active ingredient rather than a conventional cosmetic ingredient. Its regulatory status and permitted use should therefore be assessed in the target market.

Product claims should also be carefully considered, as claims that a product treats or prevents a medical condition may affect whether the product is classified as a cosmetic or medicinal product.

Ingredient Information

INCI: Tranexamic Acid
CAS: 1197-18-8
EC: 214-818-2
Molecular Formula: C₈H₁₅NO₂
Molecular Weight: 157.21 g/mol
Chemical Class: Amino Acid Derivative
Functions: Skin Conditioning Agent, Skin Brightening Agent

References

AlJabr, A., AlAnazi, A. M. I., and AlEtebi, R. A. A. “Tranexamic Acid for Hyperpigmentation Disorders: A Literature Review on Efficacy and Safety in Melasma and PIH.” Journal of Cosmetic Dermatology, 2026, 25(2), e70692. DOI: 10.1111/jocd.70692.

Maeda, K. “Mechanism of Action of Topical Tranexamic Acid in the Treatment of Melasma and Sun-Induced Skin Hyperpigmentation.” Cosmetics, 2022, 9(5), 108. DOI: 10.3390/cosmetics9050108.

Konisky, H., Balazic, E., Jaller, J. A., Khanna, U., and Kobets, K. “Tranexamic acid in melasma: A focused review on drug administration routes.” Journal of Cosmetic Dermatology, 2023, 22(4), 1197–1206. DOI: 10.1111/jocd.15589.

Na Ayuthaya, K. P., Niumphradit, N., Manosroi, A., and Nakakes, A. “Topical 5% tranexamic acid for the treatment of melasma in Asians: a double-blind randomized controlled clinical trial.” Journal of Cosmetic and Laser Therapy, 2012, 14(3), 150–154. DOI: 10.3109/14764172.2012.685478.

Kim, K. M. and Lim, H. W. “The uses of tranexamic acid in dermatology: a review.” International Journal of Dermatology, 2023, 62(5), 589–598. DOI: 10.1111/ijd.16160.

National Center for Biotechnology Information. PubChem – Tranexamic Acid.

What Is Azelaic Acid?

Azelaic acid, also known as nonanedioic acid, is a naturally occurring saturated dicarboxylic acid found in small amounts in grains such as wheat, rye and barley.

It is widely used in dermatological and cosmetic formulations, particularly products intended for blemish-prone, redness-prone and uneven-toned skin.

Cosmetic Uses of Azelaic Acid

Azelaic acid is commonly incorporated into creams, gels, lotions and other topical skin care formulations. It is associated with antimicrobial, anti-inflammatory, keratinization-modulating, antimelanogenic and antioxidant activities.

In cosmetic products, it is mainly used in formulations targeting the appearance of blemishes, uneven skin tone, redness and post-inflammatory hyperpigmentation.

Formulation Considerations

Azelaic acid has relatively low water solubility, which can make formulation challenging. Appropriate dispersion, solvent or solubilisation strategies may be required.

Particle size and dispersion quality are particularly important, as poor dispersion can result in grittiness and an uneven sensory profile. The formulation vehicle, rheology modifiers, emollients, emulsifiers and solvents should be selected according to the intended dosage form.

Ingredient Information

INCI: Azelaic Acid
Other Name: Nonanedioic Acid
CAS: 123-99-9
Chemical Class: Dicarboxylic Acid
Molecular Formula: C9H16O4
Molecular Weight: 188.22 g/mol

Source: Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

References:
Feng, X., Shang, J., Gu, Z., Gong, J., Chen, Y., and Liu, Y. “Azelaic Acid: Mechanisms of Action and Clinical Applications.” Clinical, Cosmetic and Investigational Dermatology, 2024. DOI: 10.2147/CCID.S485237.

King, S., Campbell, J., Rowe, R., Daly, M.-L., Moncrieff, G., and Maybury, C. “A systematic review to evaluate the efficacy of azelaic acid in the management of acne, rosacea, melasma and skin aging.” Journal of Cosmetic Dermatology, 2023. DOI: 10.1111/jocd.15923.

U.S. Food and Drug Administration. Azelex (azelaic acid) Cream 20% Prescribing Information.

What Is Oxybenzone?

Oxybenzone, also known as Benzophenone-3, is an organic UV filter used in sunscreen and sun care formulations. It absorbs ultraviolet radiation and is therefore incorporated into products designed for protection against sun exposure.

Cosmetic Uses of Oxybenzone

Oxybenzone is primarily used as a UV absorber in sunscreen products and other formulations where UV protection is required.

Ingredient Information

INCI: Benzophenone-3
CAS: 131-56-6
EINECS/EC: Not specified
Function: UV Absorber

Source

Dweck, Anthony. Handbook of Cosmetic Ingredients: - their use, safety and toxicology (Dweck Books 5) . Dweck Data. Kindle Edition.

What Is Ubiquinone (CoQ10)?

Ubiquinone, commonly known as Coenzyme Q10 (CoQ10), is a naturally occurring antioxidant. In cosmetic formulations, it is primarily used for its antioxidant and skin-conditioning properties.

Cosmetic Uses of Ubiquinone

Ubiquinone is used in skin care products designed to help protect the skin from free radical damage. Its antioxidant properties make it particularly suitable for formulations focused on maintaining skin condition and protecting against oxidative stress.

It can be incorporated into creams, serums, lotions and other leave-on skin care products.

Ingredient Information

INCI: Ubiquinone
CAS: 303-98-0
EINECS/EC: Not specified
Function: Skin Conditioning, Antioxidant

Source: Dweck, Anthony. Handbook of Cosmetic Ingredients: - their use, safety and toxicology (Dweck Books 5) . Dweck Data. Kindle Edition.

What Is Octinoxate?

Octinoxate, also known as Ethylhexyl Methoxycinnamate or Octyl Methoxycinnamate, is an organic UV filter used in sunscreen formulations.

Cosmetic Uses of Octinoxate

Octinoxate is primarily used as a UV filter and UV absorber in sunscreen and other sun care products. It absorbs ultraviolet radiation and is therefore incorporated into formulations designed to protect the skin from sun exposure.

The ingredient has also been reviewed by the U.S. Food and Drug Administration (FDA) for use as an active ingredient in OTC sunscreen products. The original source states an approved concentration of up to 7.5% for this use.

Ingredient Information

INCI: Ethylhexyl Methoxycinnamate
CAS: 5466-77-3
EINECS/EC: Not specified
Function: UV Filter, UV Absorber

Source: Dweck, Anthony. Handbook of Cosmetic Ingredients: - their use, safety and toxicology (Dweck Books 5) . Dweck Data. Kindle Edition.

What Is Black Seed Oil?

Nigella Sativa Seed Oil is the fixed oil expressed from the seeds of Black Caraway (Nigella sativa). It has a long history of traditional use in Arabian, Asian and African countries.

Cosmetic Uses of Black Seed Oil

Black seed oil is primarily used in cosmetics as an emollient and skin-conditioning ingredient. It can be incorporated into skin care formulations where a plant-derived oil is desired to soften and condition the skin.

The oil also possesses antimicrobial activity against several bacteria, which has contributed to interest in its topical applications. In cosmetic formulations, however, its primary functions are emollient, perfuming and skin conditioning.

Ingredient Information

INCI: Nigella Sativa Seed Oil
CAS: 90064-32-7
EINECS/EC: Not specified
Functions: Emollient, Perfuming, Skin Conditioning

Source: Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.

What Is Licorice Root Extract?

Glycyrrhiza glabra, commonly known as licorice, is a botanical ingredient obtained from the dried and ground rhizome and root of the plant. Licorice-derived ingredients have a long history of use and are also recognised for their cosmetic applications.

Cosmetic Uses of Licorice Root Extract

Licorice root extract is used in cosmetic formulations primarily for its soothing, smoothing, emollient and moisturising properties. It can be incorporated into products designed for dry, sensitive or stressed-looking skin.

It is suitable for a variety of skin care formulations, including creams, lotions, serums and other leave-on products where skin conditioning and moisturisation are desired.

The safety of licorice-derived cosmetic ingredients has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel, which concluded that the ingredients evaluated were safe for use in cosmetics.

Ingredient Information

INCI: Glycyrrhiza Glabra Root Extract
CAS: 84775-66-6
EINECS/EC: Not specified
Functions: Soothing, Smoothing, Emollient, Moisturising

Source: Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.

What Is Sesame Seed Oil?

Sesamum indicum (Sesame) Seed Oil, also known as gingilli oil, is a highly lubricious botanical oil that leaves a soft protective film on the skin. It has been used since antiquity as a gentle emollient and is also valued for its long shelf life in massage preparations.

The oil contains naturally occurring antioxidants including sesamol, sesamin, sesamolin and tocopherols.

Cosmetic Uses of Sesame Seed Oil

Sesame oil is widely used as an emollient and conditioning ingredient in skin and hair care formulations. It helps reduce the feeling of dryness and leaves the skin soft and smooth.

It can be incorporated into:

• Moisturising creams and lotions
• Barrier creams
• Massage oils
• Hair conditioning products
• Other skin-conditioning formulations

Its antioxidant content also makes sesame oil suitable for formulations focused on maintaining skin condition and protecting the skin from environmental stress.

Ingredient Information

INCI: Sesamum Indicum (Sesame) Seed Oil
CAS: 8008-74-0
EINECS/EC: Not specified
Functions: Emollient, Hair Conditioning, Skin Conditioning

Source: Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.

What Is Centella Asiatica Extract?

Centella asiatica, also known as Gotu Kola or Indian Pennywort, is a botanical ingredient that has a long history of use in traditional skin care. It contains naturally occurring compounds including asiaticoside, which has been the subject of scientific and clinical investigation.

Cosmetic Uses of Centella Asiatica

Centella asiatica extract is used in cosmetic formulations for soothing, smoothing and skin-conditioning applications. It is particularly associated with products intended for dry, rough, chapped or stressed-looking skin.

Centella asiatica extract can be incorporated into creams, lotions, serums and other topical skin care products.

Ingredient Information

INCI: Centella Asiatica Extract
CAS: 84696-21-9
EINECS/EC: Not specified
Functions: Cleansing, Skin Conditioning, Smoothing, Soothing, Tonic

Source: Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.

What Is Castor Seed Oil?

Castor seed oil is a rich botanical oil obtained from the seeds of Ricinus communis. It is known for its glossy appearance when applied to the skin and has traditionally been used as a protective and emollient ingredient.

Cosmetic Uses of Castor Seed Oil

Castor oil is widely used in cosmetic formulations for its emollient, moisturising and smoothing properties. Its glossy character makes it particularly useful in colour cosmetics and lip care.

It is commonly used in:

• Lipsticks
• Lip balms and lip salves
• Transparent soaps
• Hair grooming products

In hair care, castor oil is used to condition, soften and add gloss to the hair.

Ingredient Information

INCI: Ricinus Communis (Castor) Seed Oil
CAS: 8001-79-4
EINECS/EC: Not specified
Functions: Emollient, Skin Conditioning, Moisturising, Smoothing, Solvent

Source: Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.

What Is Vitamin E?

Vitamin E, or tocopherol, is an oil-soluble vitamin found naturally in many plant oils, particularly wheat germ oil. In cosmetics, it is valued primarily for its antioxidant and skin-conditioning properties.

As an antioxidant, tocopherol helps neutralise free radicals and can help protect lipids from oxidation. It is therefore commonly used in skin care products formulated for skin protection and the care of prematurely aged-looking skin.

Cosmetic Uses of Vitamin E

Tocopherol is widely incorporated into creams, lotions, facial oils, serums and other skin care products. Its antioxidant properties make it particularly useful in formulations intended to support the skin against oxidative stress.

Vitamin E and its derivatives, including Tocopheryl Acetate, Tocopheryl Linoleate and Tocopheryl Succinate, are also commonly used in cosmetic formulations.

The Cosmetic Ingredient Review (CIR) Expert Panel has assessed the safety of tocopherol and several related vitamin E ingredients and concluded that they are safe as used in cosmetics and personal care products.

Ingredient Information

INCI: Tocopherol
CAS: 59-02-9
EINECS/EC: Not specified
Functions: Antioxidant, Skin Conditioning

Source: Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.

What Is Green Clay (Montmorillonite)?

Montmorillonite is a refined clay composed of hydrated aluminium silicate. Its characteristic green colour can result from trace amounts of minerals such as iron within the clay structure.

Montmorillonite has properties similar to kaolin and is widely used in cosmetic and personal care formulations.

Cosmetic Uses of Montmorillonite

Montmorillonite is primarily used as an absorbent, bulking and viscosity-controlling ingredient. It can also contribute to the stability of emulsions and other cosmetic formulations.

It is particularly suitable for products where clay's absorbent properties and ability to modify formulation texture are desirable, including masks, cleansing products and other skin care preparations.

The Cosmetic Ingredient Review (CIR) Expert Panel has assessed the safety of montmorillonite and related ingredients and concluded that they are safe as used in cosmetics and personal care products.

Ingredient Information

INCI: Montmorillonite
CAS: 1318-93-0
EINECS/EC: Not specified
Functions: Absorbent, Bulking, Emulsion Stabilising, Stabilising, Viscosity Controlling

Source: Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.

What Is White Clay (Kaolin)?

Kaolin, also known as China Clay, is a naturally mined mineral consisting mainly of hydrated aluminium silicate. It has been used for many generations in pharmaceuticals, cosmetics and skin care.

Cosmetic Uses of Kaolin

Kaolin is primarily used in cosmetics for its absorbent properties and its smooth, emollient feel on the skin. It is commonly incorporated into products where absorption and powder structure are important.

Kaolin is used in:

• Face powders
• Eye shadows
• Face masks
• Scrubs

It can also function as a bulking agent in scrubs and masks, contributing to the physical structure and texture of the formulation.

Ingredient Information

INCI: Kaolin
CAS: 1332-58-7
EINECS/EC: Not specified
Functions: Absorbent, Anticaking, Abrasive, Bulking, Opacifying

Source: Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.

What Is Green Tea Extract?

Camellia sinensis leaf extract, commonly known as green tea extract, is a botanical ingredient obtained from the leaves of the tea plant. Green tea has a long history of use in traditional medicine and is widely incorporated into modern cosmetic formulations.

The extract contains naturally occurring compounds associated with antioxidant activity and is used in cosmetic products for its conditioning and toning properties.

Cosmetic Uses of Green Tea Extract

Green tea extract is commonly used in facial and body care products formulated for skin conditioning and refreshing care. Its astringent properties also make it suitable for formulations intended for oily or combination skin.

The antioxidant properties of green tea are associated particularly with its catechins and catechin gallate esters. These compounds have been investigated for their ability to counteract free-radical activity and support the protection of skin cells from oxidative stress.

Green tea extract can therefore be found in creams, lotions, serums, masks and other skin care formulations.

Ingredient Information

INCI: Camellia Sinensis Leaf Extract
CAS: 84650-60-2
EINECS/EC: Not specified
Functions: Skin Conditioning, Astringent, Tonic

Source: Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.

What Is Bakuchiol?

Bakuchiol is a natural meroterpene obtained from the seeds of Psoralea corylifolia. It has been investigated for antibacterial activity and cosmetic applications related to blemish-prone and visibly aging skin.

Cosmetic Uses of Bakuchiol

Bakuchiol is used in skin care formulations designed for blemish-prone, uneven and mature-looking skin. Research has investigated its effects on several biological processes relevant to cosmetic skin care, including collagenase and elastase activity, inflammation and microbial growth.

Bakuchiol is therefore commonly considered a botanical alternative for formulations targeting the appearance of skin aging and blemishes.

Ingredient Information

INCI: Bakuchiol
Source: Psoralea corylifolia seeds
CAS / EINECS/EC: Not specified on the original source page.

Source: Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.

What Are Alpha Hydroxy Acids?

Alpha hydroxy acids (AHAs) are a group of organic acids commonly used in cosmetic skin care for their exfoliating properties. They produce a mild exfoliating effect by helping to loosen and remove superficial dead skin cells.

Common AHAs used in cosmetics include glycolic acid, lactic acid, citric acid, malic acid and tartaric acid.

Cosmetic Uses of AHAs

AHAs are commonly incorporated into facial cleansers, toners, creams, serums and exfoliating treatments. In typical over-the-counter cosmetic products, they are used at relatively low concentrations to provide gradual exfoliation.

Regular cosmetic use can help improve the appearance of skin texture, hydration, fine lines and uneven skin tone. AHAs are therefore frequently used in products formulated for dull, rough or uneven-looking skin.

Concentration and Formulation

The concentration of AHAs varies according to the intended application. Using several AHA-containing products simultaneously can increase the risk of skin irritation and redness. Formulation, concentration and frequency of use should therefore be considered carefully.

Common Cosmetic AHAs

• Glycolic acid – commonly associated with sugar cane
• Lactic acid – naturally occurring in fermented and biological sources
• Citric acid – found in citrus fruits
• Malic acid – found in apples
• Tartaric acid – found in grapes

CAS / EINECS/EC: Not applicable to AHAs as a general ingredient category; individual acids have their own identifiers.

Source

Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.

What Is Rosa Canina Hip Seed Oil?

Rosa Canina (Dog Rose) Hip Seed Oil is a natural plant-derived lipid rich in gamma-linolenic acid (GLA). It is valued in cosmetic formulations for its emollient and skin-conditioning properties.

Cosmetic Uses of Rosehip Seed Oil

Rosehip seed oil is commonly used in skin care products formulated for dry, rough, cracked or devitalised-looking skin. Its lipid composition supports skin moisturisation and helps maintain the skin's moisture barrier.

It can be incorporated into creams, lotions, facial oils, balms and other products designed to provide emollient and conditioning benefits.

The ingredient has also been traditionally used in products for the care of skin affected by scars, pigmentation and other visible skin imperfections.

Ingredient Information

INCI: Rosa Canina Seed Oil
CAS: 84603-93-0
EINECS/EC: Not specified
Function: Emollient, Skin Conditioning

Source: Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4) . Dweck Data. Kindle Edition.