Azeco Cosmeceuticals
The interest in azelaic acid, which is a C9-dicarboxylic acid, for treating pigmented lesions thus ensued (5). This acid is produced naturally by a yeast, Malassezia furfur. Its inhibitory activity against tyrosinase is reflected in the appearance of depigmented maculae on the skin of subjects suffering from a mycosis, Pityriasis versicolor. This fungus produces lipoxygenases that are capable of acting on the unsaturated fatty acids present on the skin surface. In culture, this fungus is capable of oxidizing oleic acid into azelaic acid (6). There is unanimous agreement regarding its efficacy and absence of undesirable effects of note. A placebo-controlled clinical study conducted on 52 women with dark or pigmented skin (phototypes IV to VI) suffering from melas- ma demonstrated the superiority of a cream containing 20% azelaic acid. The women found that their skin was smoother and were thus satisfied overall (7). It seems that the preparations containing 20% azelaic acid and 4% hydroquinone are equivalent in vivo (5). The anti-inflammatory, anti-keratinizing and bacteriostatic activity of azelaic acid justifies its use in treating diseases such as rosacea or acne (8, 9). Over the treatment (of melasma) period the azelaic acid cream, compared to the hydroquinone one, yielded good or excellent results; no significant treatment differences were observed with regard to overall rating, reduction in lesion size, and pig - mentary intensity. Severe side effects such as allergic sensitization or exogenous ochronosis were not observed with azelaic acid (10). Azelaic acid is then today considered as the rising star for anti-acne OTC products. In fact, for the medical treatment of acne vulgaris a variety of preparations are commercially offered with a concentration of azelaic acid of 10-20%. Azelaic acid may be used in the personal care & cosmetic products, in medical devices and in pharmaceutical products of many countries without concentration limitations. It shows no significant side effects, it has no cytotoxic properties and does not exhibit CMR properties. The major constraint for the use of azelaic acid is its solubility. However, the solubility problem of azelaic acid can be solved using particular solvent systems or using smart formulation techniques. Because of the poor solubility the bio-availability is also limited, but that problem may simultaneously be solved while tuning the solubility. Commercial personal care preparations contain 8-12% azelaic acid, enabling to better control undesired side reactions. 2.2.1 Azelaic acid in anti-acne products The word acne comes from the Ancient Greek “acme”, meaning ‘top’ blossom or “highlight”. The word not only relates to the fact that pimples and blemishes occur as small mountain tops protruding above the skin, but also that the disease occurs primarily in peo- ple in the ‘flowering’ of their lives. In 1935, the word acne was record-ed as a new Latin medical term, taken from a misspelling of the word acme by a 6th century physician Aetius. Acne vulgaris is one of the most common skin conditions in children and adolescents. Acne is a skin disorder associated with Propionibacterium acnes (abbreviated as P.acnes). This is a slow growing gram-positive anaero- bic rod-shaped bacterium, reasonably tolerant to oxygen. It clinically manifests itself by the formation of closed and open comedones (white- or blackheads), papules (red bumps), pustules and nodules. P.acnes affects many young adults and adolescents undermining their self-esteem. Sebaceous glands may become a growth matrix for P.acnes. It feeds itself on the lipids produced in the sebaceous glands, acquiring water from the blood stream and obtaining its amino acids by destruction of the wall of the sebaceous glands. P.acnes may become opportunistic if the conditions for growth are optimal, mostly by blocking the sebaceous glands due to exces- sive sebum production that also has a higher viscosity relative to standard. The result is the formation of closed comedones. P.acnes produces enzymes that break down the wall of sebaceous glands. This leads to folliculitis which may advance to skin breakage and scarring. In some cases these scars may also get infected. In extreme cases P.acnes may be responsible for endocarditis. The conse- quences of acne may be quite severe indeed. A variety of treatments are available to resolve acne, but basically all treatments use harsh ingredients such as benzoyl peroxide, salicylic acid, elementary sulphur, zinc compounds, antibiotics (e.g. clindamycin, doxycycline) or tretinoin. Most of these products are strictly forbidden in personal care & cosmetic products, and are made available only as prescription drugs. The side effects are certainly not to be ignored, as these ingredients not only resolve acne but also affect the native microflora present on the skin.
Phone : 0031475 782540 • info@azeco-cosmeceuticals.com • www.azeco-cosmeceuticals.com
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