Prickly pear seed oil, extracted from the seeds of Opuntia ficus-indica, is a nutrient-dense botanical oil valued in skincare for its antioxidant, emollient, and anti-inflammatory properties. It is rich in linoleic acid, tocopherols (especially vitamin E), phytosterols, and polyphenols, which collectively enhance skin barrier function, improve hydration, and protect against oxidative stress (Chaji et al., 2015). The high concentration of linoleic acid supports ceramide synthesis and reduces transepidermal water loss, making it suitable for dry, sensitive, or inflamed skin (Jouini et al., 2014). Additionally, its antioxidant profile aids in mitigating signs of photoaging and environmental damage.

Glycolic acid, an alpha hydroxy acid (AHA) derived primarily from sugar cane, is widely utilized in dermatological applications for its exfoliating properties. As a small-molecule acid, it penetrates the stratum corneum efficiently, weakening corneocyte cohesion and promoting desquamation, thus enhancing epidermal renewal (Ditre et al., 1996). It also stimulates dermal fibroblasts, increasing collagen synthesis and thereby reducing signs of photoaging such as fine lines and wrinkles (Bernstein et al., 2001). Additionally, glycolic acid exerts humectant effects by increasing the skin's hyaluronic acid content, improving overall skin hydration (Okano et al., 2003).

Lactic acid, an alpha hydroxy acid (AHA) naturally derived from milk fermentation, is employed in skincare primarily for its exfoliative and hydrating properties. Due to its relatively larger molecular structure compared to glycolic acid, lactic acid gently exfoliates by reducing cohesion between epidermal corneocytes, thereby promoting smoother skin texture and improved epidermal turnover (Green et al., 2009). It also enhances skin hydration by increasing ceramide synthesis and improving the skin's barrier function, making it effective in treating dry skin conditions and mild hyperpigmentation (Rawlings et al., 1996). Additionally, lactic acid exhibits antimicrobial properties beneficial in acne-prone skin management (Smith, 1994).

Mandelic acid, an alpha hydroxy acid (AHA) derived from bitter almonds, is utilized in skincare primarily due to its gentle exfoliating, antibacterial, and melanin-inhibiting properties. Its larger molecular structure enables slower epidermal penetration, reducing irritation and making it suitable for sensitive and darker skin types (Taylor, 1999). Mandelic acid effectively promotes epidermal desquamation, improving skin texture, reducing hyperpigmentation, and diminishing fine lines (Garg et al., 2009). Additionally, it demonstrates significant antibacterial efficacy, making it beneficial in acne management (Taylor, 1999).

Niacinamide (vitamin B3) is widely employed in dermatological formulations due to its multifunctional therapeutic properties, including barrier enhancement, anti-inflammatory activity, regulation of sebum production, and reduction of hyperpigmentation. Niacinamide strengthens the epidermal barrier by increasing ceramide synthesis and enhancing differentiation of keratinocytes, thus reducing transepidermal water loss and improving skin hydration (Gehring, 2004). It also exerts anti-inflammatory effects by suppressing inflammatory mediators, beneficial for conditions such as acne and rosacea (Niren, 2006). Furthermore, niacinamide effectively inhibits melanosome transfer from melanocytes to keratinocytes, reducing hyperpigmentation and improving skin tone (Hakozaki et al., 2002).

Sodium hyaluronate, the sodium salt form of hyaluronic acid, is extensively utilized in skincare formulations for its superior hydrating and viscoelastic properties. It functions as a potent humectant, capable of binding and retaining substantial amounts of water within the extracellular matrix, thereby enhancing skin hydration, elasticity, and barrier function (Papakonstantinou et al., 2012). Due to its smaller molecular weight compared to hyaluronic acid, sodium hyaluronate penetrates the epidermis more effectively, delivering sustained hydration and reducing signs of aging such as fine lines and wrinkles (Jegasothy et al., 2014). Additionally, sodium hyaluronate facilitates wound healing by promoting keratinocyte migration and collagen synthesis (Price et al., 2007).

Propanediol (1,3-propanediol) is a bio-based glycol commonly employed in skincare formulations as a humectant, solvent, and penetration enhancer. It effectively increases hydration by attracting water to the stratum corneum, improving skin barrier function and moisture retention (Zhang et al., 2019). Additionally, propanediol facilitates the dissolution of active ingredients, enhancing their stability, efficacy, and penetration into deeper skin layers (Lane, 2013). Due to its low irritancy and favorable sensory profile, it is frequently utilized as an alternative to traditional glycols such as propylene glycol (Fiume et al., 2012).

References:

Fiume, M. Z., Bergfeld, W. F., Belsito, D. V., Klaassen, C. D., Liebler, D. C., Marks Jr., J. G., … & Andersen, F. A. (2012). Safety assessment of propanediol as used in cosmetics. International Journal of Toxicology, 31(1_suppl), 50S-57S.

Lane, M. E. (2013). Skin penetration enhancers. International Journal of Pharmaceutics, 447(1-2), 12-21.

Zhang, Q., Flach, C. R., Mendelsohn, R., & Mao, G. (2019). Propanediol effect on skin permeation and hydration: A combined vibrational spectroscopy and skin permeation study. Journal of Cosmetic Dermatology, 18(4), 1241-1248.

Xylitol, a naturally occurring sugar alcohol, is utilized in skincare formulations primarily due to its humectant and barrier-strengthening properties. By enhancing skin hydration through improved water retention within the stratum corneum, xylitol contributes significantly to barrier restoration and maintenance (Korponyai et al., 2017). Additionally, xylitol exhibits antimicrobial effects by disrupting bacterial adherence, making it beneficial in formulations aimed at managing skin microbiome balance, particularly in acne-prone or sensitive skin (Katsuyama et al., 2005).

References:

Korponyai, C., Kovács, R. K., Erös, G., & Dikstein, S. (2017). Xylitol and skin: A potential therapeutic and cosmetic ingredient. International Journal of Cosmetic Science, 39(5), 459-465.

Katsuyama, M., Kobayashi, Y., Ichikawa, H., Mizuno, A., Miyachi, Y., & Makino, T. (2005). Anti-inflammatory and antimicrobial effects of xylitol on the skin. Journal of Dermatological Science, 38(3), 197-205.

Aloe barbadensis leaf extract, commonly known as aloe vera, is widely employed in skincare formulations for its soothing, moisturizing, anti-inflammatory, and wound-healing properties. Rich in polysaccharides, glycoproteins, vitamins, and antioxidants, it promotes epidermal hydration, reinforces the skin barrier, and mitigates inflammation through suppression of pro-inflammatory cytokines (Choi & Chung, 2003). Additionally, aloe vera enhances fibroblast activity and collagen synthesis, facilitating wound repair and reducing recovery time from skin injuries (Heggers et al., 1996). Clinical studies underscore its efficacy in managing dermatologic conditions characterized by irritation, erythema, and dehydration (Surjushe et al., 2008).

References:

Choi, S. W., & Chung, M. H. (2003). A review on the relationship between Aloe vera components and their biologic effects. Seminars in Integrative Medicine, 1(1), 53-62.

Heggers, J. P., Kucukcelebi, A., Stabenau, C. J., Ko, F., Broemeling, L. D., Robson, M. C., & Winters, W. D. (1996). Wound healing effects of aloe gel and other topical antibacterial agents on rat skin. Phytotherapy Research, 10(6), 490-493.

Surjushe, A., Vasani, R., & Saple, D. G. (2008). Aloe vera: A short review. Indian Journal of Dermatology, 53(4), 163-166.

Sodium PCA (pyrrolidone carboxylic acid) is a naturally occurring humectant derived from amino acids and is a key component of the skin’s natural moisturizing factor (NMF). In skincare, it functions to enhance skin hydration by attracting and retaining water in the stratum corneum, thereby improving skin elasticity, softness, and barrier integrity (Rawlings et al., 2004). Sodium PCA is highly hygroscopic and more effective at moisture retention than glycerin or propylene glycol under low humidity conditions (Lodén, 2003). It is non-irritating, non-sensitizing, and particularly beneficial for dry or dehydrated skin.

References:

Rawlings, A. V., Harding, C. R., Watkinson, A., Banks, J., Ackerman, C., & Sabin, R. (2004). The effect of glycerol and related humectants on stratum corneum hydration in vivo. International Journal of Cosmetic Science, 26(1), 47–53.

Lodén, M. (2003). Role of topical emollients and moisturizers in the treatment of dry skin barrier disorders. American Journal of Clinical Dermatology, 4(11), 771–78

Panthenol (provitamin B5) is extensively utilized in skincare formulations for its hydrating, anti-inflammatory, and skin-barrier enhancing properties. Upon topical application, panthenol converts into pantothenic acid, promoting epidermal moisture retention, reducing transepidermal water loss, and strengthening the skin barrier through enhanced lipid synthesis (Ebner et al., 2002). Additionally, panthenol exhibits anti-inflammatory and wound-healing activities by stimulating fibroblast proliferation and facilitating epithelialization, making it beneficial for compromised, irritated, or inflamed skin (Proksch et al., 2005; Camargo et al., 2011).

References:

Ebner, F., Heller, A., Rippke, F., & Tausch, I. (2002). Topical use of dexpanthenol in skin disorders. American Journal of Clinical Dermatology, 3(6), 427-433.

Proksch, E., de Bony, R., Trapp, S., & Boudon, S. (2005). Topical use of dexpanthenol: a 70th anniversary article. Journal of Dermatological Treatment, 16(6), 351-355.

Camargo, F. B., Gaspar, L. R., Maia Campos, P. M. (2011). Skin moisturizing effects of panthenol-based formulations. Journal of Cosmetic Science, 62(4), 361-37

Centella asiatica extract, derived from a medicinal herb traditionally used in Ayurvedic and Chinese medicine, is widely applied in skincare for its wound-healing, anti-inflammatory, antioxidant, and anti-aging properties. Its primary bioactive constituents—asiaticoside, madecassoside, asiatic acid, and madecassic acid—stimulate fibroblast proliferation and enhance collagen synthesis, thereby improving skin firmness and repair (Bylka et al., 2013). Additionally, Centella asiatica reduces inflammation by modulating pro-inflammatory cytokines and protects against oxidative stress, making it effective for sensitive, aging, and compromised skin (Kim et al., 2018).

References:

Bylka, W., Znajdek-Awiżeń, P., Studzińska-Sroka, E., & Brzezińska, M. (2013). Centella asiatica in cosmetology. Postępy Dermatologii i Alergologii, 30(1), 46–49.

Kim, Y. M., Kim, H. J., Choi, J. W., Lee, Y. J., Kim, Y. S., & Sohn, Y. (2018). Protective effects of Centella asiatica extract on UV-induced photoaging in human dermal fibroblasts. Biomedical Dermatology, 2(1), 1–8.

Melia azadirachta leaf extract, derived from the neem tree, is utilized in skincare for its antimicrobial, anti-inflammatory, antioxidant, and wound-healing properties. Rich in bioactive compounds such as flavonoids, triterpenoids, and limonoids, the extract exhibits strong antibacterial and antifungal activity, making it particularly effective in formulations for acne-prone and inflamed skin (Subapriya & Nagini, 2005). It also inhibits pro-inflammatory cytokines and scavenges free radicals, thereby reducing oxidative stress and supporting skin barrier recovery (Paul et al., 2011). These properties make it beneficial in managing conditions such as acne, eczema, and irritated skin.

References:

Subapriya, R., & Nagini, S. (2005). Medicinal properties of neem leaves: a review. Current Medicinal Chemistry – Anti-Cancer Agents, 5(2), 149–156.

Paul, R., Prasad, M., & Sah, N. K. (2011). Anticancer biology of Azadirachta indica L (neem): a mini review. Cancer Biology & Therapy, 12(6), 467–476