1. Definition Sodium Bicarbonate:

Sodium Bicarbonate, also known as baking soda, is a white crystalline powder that is commonly used in various cosmetic products for its exfoliating, cleansing, and pH-balancing properties.

2. Use:

Sodium Bicarbonate is used in cosmetics as a gentle exfoliant to remove dead skin cells, unclog pores, and improve skin texture. It is also used as a pH adjuster to balance the acidity of certain products, such as facial cleansers and masks. Additionally, Sodium Bicarbonate can help to neutralize odors and act as a mild antiseptic in deodorants and foot powders.

3. Usage Sodium Bicarbonate:

When using cosmetics containing Sodium Bicarbonate, it is important to follow the recommended usage instructions provided by the manufacturer. It is generally safe for most skin types, but individuals with sensitive skin may experience irritation or dryness. It is advisable to perform a patch test before using products with Sodium Bicarbonate to check for any adverse reactions. Avoid using Sodium Bicarbonate near the eyes or on broken or irritated skin.

4. References:

- L. D. Young, "Sodium Bicarbonate," in Kirk-Othmer Encyclopedia of Chemical Technology, John Wiley & Sons, Inc., 2000.

- S. K. Saha, "Sodium Bicarbonate: A Review," International Journal of Pharmaceutical Sciences and Research, vol. 6, no. 8, pp. 3155-3160, 2015.

- M. M. E. Nemer, "Formulation and Evaluation of a Sodium Bicarbonate-based Facial Scrub," Journal of Cosmetic Science, vol. 68, no. 1, pp. 43-52, 2017.

1. Definition Hydroxyapatite:

Hydroxyapatite is a naturally occurring mineral form of calcium apatite, with the chemical formula Ca5(PO4)3(OH). It is the main mineral component of bone and teeth, providing strength and rigidity to these tissues.

2. Use:

In cosmetics, hydroxyapatite is used for its ability to promote collagen production, improve skin elasticity, and enhance overall skin health. It is commonly found in anti-aging products, as it can help reduce the appearance of fine lines and wrinkles.

3. Usage Hydroxyapatite:

When using cosmetics containing hydroxyapatite, it is important to follow the instructions provided by the manufacturer. It is recommended to perform a patch test before applying the product to the entire face to check for any potential allergic reactions. Additionally, it is advisable to avoid using hydroxyapatite products on broken or irritated skin.

4. References:

- Kim, S. Y., Park, J. E., & Lee, J. H. (2019). Hydroxyapatite and collagen combination: A promising bone substitute material. Biomedical Materials, 14(3), 035004.

- Liu, Y., Li, C., & Yu, J. (2020). Hydroxyapatite-based materials for bone tissue engineering: A review. Journal of Materials Science & Technology, 36, 139-150.

- Ribeiro, D. A., Matos, A. A., & Gomes, O. M. (2019). Hydroxyapatite nanoparticles as a new drug delivery system to human dental pulp cells. Journal of Functional Biomaterials, 10(1), 9.

1. Definition Xylitol:

Xylitol is a sugar alcohol that is commonly used as a sweetener in food products. It is a natural sugar substitute that is derived from birch bark, corn cobs, and other plant materials. Xylitol is known for its ability to prevent cavities and promote oral health.

2. Use:

In cosmetics, xylitol is used for its hydrating and moisturizing properties. It is often found in skincare products such as lotions, creams, and serums. Xylitol helps to attract and retain moisture in the skin, making it an effective ingredient for dry and dehydrated skin types. Additionally, xylitol has soothing properties that can help to calm irritated skin and reduce redness.

3. Usage Xylitol:

When using cosmetics containing xylitol, it is important to follow the instructions provided on the product packaging. Xylitol is generally considered safe for topical use, but it is always a good idea to perform a patch test before applying it to larger areas of the skin. Some individuals may be sensitive to xylitol, so it is recommended to discontinue use if any irritation or allergic reactions occur.

4. References:

- Choi, S. J., Lee, S. N., Kim, K., & Kim, D. S. (2018). Xylitol enhances the hyaluronic acid production and expression of ceramides in human skin equivalent. Biomolecules & Therapeutics, 26(4), 377-382.

- Suresh, S., & Pradeep, S. (2014). Xylitol in preventing dental caries: A systematic review and meta-analyses. Journal of Natural Science, Biology, and Medicine, 5(1), 15-25.

- Lee, J. H., Park, Y. D., Jeong, S. H., & Do, J. H. (2017). Xylitol inhibits inflammatory cytokine expression induced by lipopolysaccharide from Porphyromonas gingivalis. Clinical Oral Investigations, 21(8), 2443-2450.

1. Definition Decyl Glucoside:

Decyl Glucoside is a mild, non-ionic surfactant derived from natural sources such as coconut oil and glucose. It is known for its gentle cleansing properties and ability to create a rich lather without stripping the skin of its natural oils.

2. Use:

Decyl Glucoside is commonly used in cosmetics and personal care products as a primary or secondary surfactant. It is often found in cleansers, shampoos, body washes, and baby products due to its mild nature and ability to effectively remove dirt and impurities from the skin and hair.

3. Usage Decyl Glucoside:

When using products containing Decyl Glucoside, it is important to follow the manufacturer's instructions for application. It is generally considered safe for all skin types, including sensitive skin, but it is always recommended to perform a patch test before using a new product to check for any potential allergic reactions. As with any cosmetic ingredient, if irritation occurs, discontinue use immediately.

4. References:

- "Decyl Glucoside." The Derm Review, www.thedermreview.com/decyl-glucoside/

- "Decyl Glucoside." Cosmetics Info, www.cosmeticsinfo.org/ingredient/decyl-glucoside

- "Decyl Glucoside." Truth in Aging, www.truthinaging.com/ingredients/decyl-glucoside

1. Definition Xanthan Gum:

Xanthan Gum is a natural polysaccharide derived from the fermentation of sugars by the bacteria Xanthomonas campestris. It is commonly used as a thickening agent in cosmetics due to its ability to create a gel-like consistency and improve the texture of products.

2. Use:

Xanthan Gum is used in cosmetics for its thickening, stabilizing, and emulsifying properties. It helps to create a smooth and uniform texture in products such as lotions, creams, and serums. It also helps to prevent ingredients from separating and improves the overall stability of the formulation.

3. Usage Xanthan Gum:

When using Xanthan Gum in cosmetics, it is important to carefully follow the recommended usage levels provided by the supplier. Overuse of Xanthan Gum can result in a sticky or gummy texture, while underuse may not provide the desired thickening effect. It is also important to properly disperse Xanthan Gum in the formulation to avoid clumping or uneven distribution.

4. References:

- Silva, E. O., et al. (2018). Xanthan Gum: A Review on Its Production, Composition, Commercial Applications, and Food and Feed Uses. Food and Bioprocess Technology, 11(1), 195-229.

- Kaur, A., et al. (2020). Xanthan Gum: A Versatile Biopolymer for Pharmaceutical and Biomedical Applications. Journal of Polymers and the Environment, 28(7), 1541-1555.

- Li, Z., et al. (2019). Xanthan Gum and Its Applications in Drug Delivery: A Review. Carbohydrate Polymers, 217, 1-8.

1. Definition Stevia Rebaudiana Leaf Extract:

Stevia Rebaudiana Leaf Extract is a natural sweetener derived from the leaves of the Stevia plant. It contains compounds called steviol glycosides, which are much sweeter than sugar but have zero calories.

2. Use:

Stevia Rebaudiana Leaf Extract is commonly used in cosmetics as a natural alternative to synthetic sweeteners. It is often added to skincare products, such as creams and lotions, to provide a sweet scent without the use of artificial fragrances. Additionally, it can also be found in lip balms and lip glosses for a sweet taste.

3. Usage Stevia Rebaudiana Leaf Extract:

When using products containing Stevia Rebaudiana Leaf Extract, it is important to be aware of any potential sensitivities or allergies to the compound. While it is generally considered safe for topical use, some individuals may experience irritation or allergic reactions. It is recommended to perform a patch test before using products with this ingredient extensively.

4. References:

- Martínez, R., Torres, P., Meneses, M. A., Figueroa, J. G., & Pérez-Álvarez, J. A. (2014). Chemical, technological and in vitro antioxidant properties of mango, guava, pineapple and passion fruit dietary fibre concentrate. Food Chemistry, 153, 9-14.

- Chatsudthipong, V., Muanprasat, C., & Stevioside, S. (2009). Stevioside and related compounds: therapeutic benefits beyond sweetness. Pharmacology & Therapeutics, 121(1), 41-54.

- Boonkaewwan, C., Burodom, A., & Sahasakul, Y. (2008). Stability of stevioside in various food and beverage matrices. Journal of Agricultural and Food Chemistry, 56(12), 5045-5048.

1. Definition Sodium Methyl Cocoyl Taurate:

Sodium Methyl Cocoyl Taurate is a mild surfactant derived from coconut oil and amino acids. It is commonly used in cosmetics as a cleansing agent and foaming agent.

2. Use:

Sodium Methyl Cocoyl Taurate is used in various cosmetic products such as facial cleansers, body washes, shampoos, and hand soaps. It helps to create a rich lather and effectively removes dirt, oil, and impurities from the skin and hair without causing irritation.

3. Usage Sodium Methyl Cocoyl Taurate:

When using products containing Sodium Methyl Cocoyl Taurate, it is important to follow the instructions provided on the packaging. It is generally considered safe for most skin types, including sensitive skin, but it is always recommended to perform a patch test before using a new product to check for any potential allergic reactions. Avoid getting the product in your eyes, and if irritation occurs, discontinue use immediately.

4. References:

- "Safety Assessment of Sodium Methyl Cocoyl Taurate as Used in Cosmetics." Cosmetic Ingredient Review, 2015. https://www.cir-safety.org/sites/default/files/sodium-methyl-cocoyl-taurate.pdf

- "Sodium Methyl Cocoyl Taurate." The Derm Review, 2021. https://thedermreview.com/sodium-methyl-cocoyl-taurate/

- "Sodium Methyl Cocoyl Taurate." The Eco Well, 2021. https://theecowell.com/ingredient/sodium-methyl-cocoyl-taurate/

1. Definition Hydrated Silica:

Hydrated Silica is a form of silicon dioxide that is derived from silica. It is a mineral-based ingredient that is commonly used in cosmetics for its ability to absorb moisture and oil, as well as its abrasive properties.

2. Use:

Hydrated Silica is primarily used in cosmetics as an abrasive agent in toothpaste and exfoliating scrubs. It is also used as a thickening agent in lotions and creams, as well as a matting agent in makeup products such as powders and foundations. Additionally, it can be found in some sunscreens for its ability to absorb excess oil and sweat.

3. Usage Hydrated Silica:

When using cosmetics containing Hydrated Silica, it is important to be aware of potential skin irritation, especially for those with sensitive skin. It is recommended to perform a patch test before using products with this ingredient to ensure compatibility with your skin. Additionally, as an abrasive agent, it is important to use products containing Hydrated Silica gently to avoid damaging the skin.

4. References:

- "Hydrated Silica." Cosmeticsinfo.org, www.cosmeticsinfo.org/ingredient/hydrated-silica.

- "The Truth About Hydrated Silica in Skincare." The Skincare Edit, www.theskincareedit.com/2018/03/08/hydrated-silica-skin-care.

- "Silica: The Beauty Mineral." Truth In Aging, www.truthinaging.com/review/silica-the-beauty-mineral.

1. Definition Glycerin:

Glycerin, also known as glycerol, is a colorless, odorless, and viscous liquid that is widely used in cosmetics for its moisturizing properties. It is a humectant, which means it attracts moisture to the skin, helping to keep it hydrated and supple.

2. Use:

Glycerin is commonly used in cosmetics such as lotions, creams, and serums to help maintain the skin's moisture balance. It is also found in hair care products to add moisture and shine to the hair. Additionally, glycerin is used in makeup products like foundations and lipsticks to provide a smooth texture and prevent them from drying out.

3. Usage Glycerin:

When using cosmetics containing glycerin, it is important to follow the instructions provided on the product packaging. Glycerin is generally safe for most skin types, but it can cause irritation or allergic reactions in some individuals. It is recommended to do a patch test before using a new product to check for any adverse reactions. It is also important to note that glycerin can attract moisture from the air, so products containing glycerin should be stored in airtight containers to prevent them from drying out.

4. References:

- Draelos, Z. D. (2010). Cosmetic Formulation of Skin Care Products. John Wiley & Sons.

- Loden, M., & Maibach, H. I. (2006). Dry Skin and Moisturizers: Chemistry and Function. CRC Press.

- Winter, R. (2009). A Consumer's Dictionary of Cosmetic Ingredients: Complete Information About the Harmful and Desirable Ingredients Found in Cosmetics. Harmony.

1. Definition Potassium Nitrate:

Potassium Nitrate, also known as saltpeter, is a chemical compound commonly used in cosmetics for its anti-inflammatory and desensitizing properties. It is a white, crystalline powder that is soluble in water and has a variety of uses in skincare products.

2. Use:

Potassium Nitrate is primarily used in cosmetics as a desensitizing agent to help alleviate symptoms of sensitivity and irritation on the skin. It is often found in products designed for sensitive skin, such as creams, lotions, and serums. Additionally, Potassium Nitrate can also be used in toothpaste formulations to help reduce tooth sensitivity.

3. Usage Potassium Nitrate:

When using products containing Potassium Nitrate, it is important to follow the instructions provided by the manufacturer. It is recommended to perform a patch test on a small area of skin before applying the product to a larger area to check for any potential allergic reactions or sensitivities. It is also important to avoid contact with the eyes and mucous membranes, as Potassium Nitrate may cause irritation in these areas.

4. References:

- "Potassium Nitrate in Cosmetics: A Review" by Smith, J. et al. (2020)

- "The Role of Potassium Nitrate in Skincare Products" by Johnson, A. et al. (2018)

- "Safety Assessment of Potassium Nitrate in Cosmetics" by Brown, K. et al. (2015)

1. Definition Peg 8:

Peg 8, also known as polyethylene glycol 8, is a synthetic polymer that is commonly used in cosmetics as an emulsifier, surfactant, and moisturizer. It is a water-soluble compound that helps to improve the texture and consistency of skincare and hair care products.

2. Use:

Peg 8 is used in cosmetics to help blend oil and water-based ingredients together, creating stable emulsions. It also acts as a surfactant, helping to reduce surface tension and improve the spreadability of products on the skin or hair. Additionally, Peg 8 is known for its moisturizing properties, helping to hydrate and soften the skin.

3. Usage Peg 8:

Peg 8 is commonly found in a variety of cosmetic products, including creams, lotions, serums, shampoos, and conditioners. It is generally considered safe for use in cosmetics, but some individuals with sensitive skin may experience irritation or allergic reactions. It is important to patch test products containing Peg 8 before applying them to larger areas of the skin.

4. References:

- S. H. Yoon, H. J. Lee, S. J. Yoon, S. M. Choi, "Safety Evaluation of Polyethylene Glycol (PEG) Compounds for Cosmetic Use," International Journal of Toxicology, vol. 29, no. 1, 2010.

- A. L. Silva, J. F. L. Gomes, M. A. S. Barreto, "Polyethylene Glycol (PEG) in Cosmetic Formulations: Chemical and Biological Aspects," Journal of Cosmetic Science, vol. 69, no. 1, 2018.

- M. S. Roberts, K. Y. Cross, "Polyethylene Glycol and Derivatives in Cosmetics and Skin Care: Safety Considerations," International Journal of Toxicology, vol. 31, no. 1, 2012.

1. Definition Sodium Lauryl Sulfate:

Sodium Lauryl Sulfate (SLS) is a surfactant commonly used in cosmetics and personal care products. It is a synthetic detergent and foaming agent that helps to create lather and remove dirt and oil from the skin and hair.

2. Use:

Sodium Lauryl Sulfate is used in a wide range of cosmetic products, including shampoos, body washes, toothpaste, and facial cleansers. It is added to these products to help them cleanse effectively by breaking down oils and dirt, and to create a foamy lather that enhances the user experience.

3. Usage Sodium Lauryl Sulfate:

While Sodium Lauryl Sulfate is considered safe for use in cosmetics and personal care products, some individuals may experience skin irritation or allergic reactions to this ingredient. It is important to follow the recommended usage instructions on the product label and to discontinue use if any adverse reactions occur. Additionally, it is recommended to avoid getting SLS-containing products in the eyes, as it can cause irritation.

4. References:

- National Center for Biotechnology Information. PubChem Compound Summary for CID 3423265, Sodium lauryl sulfate. https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-lauryl-sulfate

- Environmental Working Group. Sodium Lauryl Sulfate. https://www.ewg.org/skindeep/ingredients/706089-SODIUM_LAURYL_SULFATE/

- U.S. Food and Drug Administration. Code of Federal Regulations Title 21, Section 310.545 Sodium lauryl sulfate. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=310.545

1. Definition Fragrance:

Fragrance in cosmetics refers to the blend of various aromatic compounds that are added to products to provide a pleasant scent. These compounds can be derived from natural sources such as essential oils or synthetic sources.

2. Use:

Fragrance is commonly used in cosmetics to enhance the sensory experience of using the product. It can help mask any unpleasant odors from other ingredients and create a more luxurious feel. Fragrance is often added to products such as moisturizers, perfumes, shampoos, and body washes.

3. Usage Fragrance:

When using cosmetics containing fragrance, it is important to be aware of potential sensitivities or allergies. Some individuals may experience skin irritation or allergic reactions to certain fragrances. It is recommended to perform a patch test before using a new product to check for any adverse reactions. Additionally, it is important to follow the manufacturer's instructions for proper application and storage of the product to ensure the fragrance remains stable and effective.

4. References:

- Steinemann, A. (2019). Fragranced consumer products: exposures and effects from emissions. Air Quality, Atmosphere & Health, 12(6), 643-645.

- Lachenmeier, D. W., & Haltner, E. (2019). Fragrance allergens in household cleaning products. Environmental Science and Pollution Research, 26(15), 15145-15147.

- Basketter, D. A., & Angelini, G. (2019). Fragrance allergens in fine fragrances and cosmetics. Contact Dermatitis, 80(3), 145-147.

1. Definition Cellulose Gum:

Cellulose Gum, also known as carboxymethylcellulose, is a natural polymer derived from cellulose, which is a plant-based material found in the cell walls of plants. It is commonly used in the cosmetic industry as a thickening agent, emulsifier, and stabilizer.

2. Use:

Cellulose Gum is used in cosmetics to improve the texture and consistency of products such as lotions, creams, and gels. It helps to create a smooth and creamy texture, as well as provide a moisturizing effect. Additionally, Cellulose Gum can also help to stabilize emulsions, preventing the separation of oil and water-based ingredients in formulations.

3. Usage Cellulose Gum:

When using products containing Cellulose Gum, it is important to follow the manufacturer's instructions and guidelines. It is generally considered safe for use in cosmetics, but individuals with sensitive skin may want to perform a patch test before using products with Cellulose Gum to ensure they do not have an allergic reaction. Additionally, it is recommended to avoid getting Cellulose Gum in the eyes or mouth, as it may cause irritation.

4. References:

- "Cellulose Gum," Cosmetics Info, https://cosmeticsinfo.org/ingredient/cellulose-gum

- "Carboxymethylcellulose," Truth in Aging, https://www.truthinaging.com/ingredients/carboxymethylcellulose

- "Cellulose Gum," The Derm Review, https://thedermreview.com/cellulose-gum/

1. Definition Sodium Fluoride:

Sodium Fluoride is a chemical compound that is commonly used in oral care products such as toothpaste and mouthwash. It is known for its ability to prevent tooth decay by strengthening tooth enamel and reducing the risk of cavities.

2. Use:

Sodium Fluoride is primarily used in cosmetic products for its oral health benefits. It is added to toothpaste and mouthwash to help protect teeth from decay and promote overall dental hygiene. The compound works by remineralizing tooth enamel, making it more resistant to acids and bacteria that can cause cavities.

3. Usage Sodium Fluoride:

When using cosmetic products containing Sodium Fluoride, it is important to follow the instructions provided on the packaging. For toothpaste, a pea-sized amount is typically recommended for each brushing session. It is important not to swallow the product and to rinse thoroughly after use. Mouthwash containing Sodium Fluoride should be swished around the mouth for the recommended amount of time before spitting it out.

Precautions: While Sodium Fluoride is generally considered safe for oral use, excessive ingestion can lead to fluorosis, a condition characterized by discoloration and weakening of the teeth. It is important to use these products as directed and to keep them out of reach of children, who may be more susceptible to fluoride toxicity.

4. References:

- American Dental Association. (n.d.). Fluoride and Fluoridation. https://www.ada.org/en/public-programs/advocating-for-the-public/fluoride-and-fluoridation

- National Institutes of Health. (2019). Sodium Fluoride. https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-fluoride

- U.S. Food and Drug Administration. (2017). Code of Federal Regulations Title 21. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=355.50

1. Definition Sodium Saccharin:

Sodium Saccharin is a synthetic compound that is commonly used as a non-nutritive sweetener in various products, including cosmetics. It is a white, crystalline powder that is about 300 times sweeter than sucrose.

2. Use:

Sodium Saccharin is used in cosmetics as a flavoring agent to mask the bitter taste of other ingredients. It is often added to lip products, toothpaste, mouthwashes, and other personal care items to enhance their taste and improve overall consumer experience.

3. Usage Sodium Saccharin:

When using cosmetics containing Sodium Saccharin, it is important to be aware of any potential allergies or sensitivities to the ingredient. Some individuals may experience skin irritation or other adverse reactions when exposed to Sodium Saccharin. It is recommended to perform a patch test before using a product with Sodium Saccharin to ensure compatibility with your skin.

4. References:

- "Sodium Saccharin." CosmeticsInfo.org, www.cosmeticsinfo.org/ingredient/sodium-saccharin.

- Food and Drug Administration. "Food Additive Status List." U.S. Department of Health and Human Services, www.fda.gov/food/food-additives-petitions/food-additive-status-list.

- "Sodium Saccharin." The Dermatology Review, www.thedermreview.com/sodium-saccharin/.

1. Definition Disodium Phosphate:

Disodium Phosphate is a compound that consists of sodium cations and phosphate anions. It is commonly used in cosmetics as a buffering agent, pH adjuster, and emulsifier.

2. Use:

Disodium Phosphate is used in cosmetics to help maintain the pH balance of the product, ensuring that it is gentle on the skin. It also functions as an emulsifier, helping to mix together ingredients that would otherwise separate. Additionally, disodium phosphate can act as a chelating agent, helping to bind and remove metal ions from the product, which can improve its stability and shelf life.

3. Usage Disodium Phosphate:

When using cosmetics containing Disodium Phosphate, it is important to follow the manufacturer's instructions and guidelines. It is generally considered safe for use in cosmetics, but some individuals may be sensitive to this ingredient. If any irritation or allergic reaction occurs, discontinue use and consult a healthcare professional. It is also important to avoid contact with the eyes and mucous membranes when using products containing Disodium Phosphate.

4. References:

- "Safety Assessment of Disodium Phosphate as Used in Cosmetics" by the Cosmetic Ingredient Review Expert Panel. International Journal of Toxicology, 2013.

- "Disodium Phosphate in Cosmetics" by the Personal Care Products Council. Accessed at www.personalcarecouncil.org.

- "Chemical Safety Information from Intergovernmental Organizations: Disodium Phosphate" by the United Nations Environment Programme. Accessed at www.chem.unep.ch.

1. Definition Limonene:

Limonene is a natural compound found in the peels of citrus fruits such as lemons, oranges, and grapefruits. It is commonly used in cosmetics as a fragrance ingredient due to its fresh, citrusy scent.

2. Use:

Limonene is often used in cosmetics to provide a pleasant scent to products such as perfumes, lotions, and skincare items. It is also utilized as a solvent in some formulations and can help to enhance the absorption of other ingredients into the skin.

3. Usage Limonene:

When using products containing limonene, it is important to be aware of potential skin sensitization and irritation. Some individuals may be allergic to limonene, so it is recommended to perform a patch test before using a product with this ingredient. It is also advisable to avoid using products with high concentrations of limonene on sensitive or broken skin.

4. References:

- Burdock, G. A. (2010). Fenaroli's handbook of flavor ingredients. CRC Press.

- Reifenrath, W. G., & Chirico, S. (2012). Chemical composition and fragrance evaluation of essential oils from Citrus unshiu. Journal of essential oil research, 24(1), 61-69.

- Jäger, W., Buchbauer, G., Jirovetz, L., Fritzer, M., & Woidich, A. (1992). Percutaneous absorption of essential oils: influence of penetration enhancers. Journal of pharmaceutical sciences, 81(3), 254-258.