Azeco Cosmeceuticals

Formulations

30. Question: What is the most effective level of use for treating androgenic alopecia? We have so far put the Azelaic acid into propylene glycol and glycerine with some ethanol, but this can be too heavy. What is the best mixture to use as a carrier? Do you have a sample formulation available as a guide? Answer: This answer relates to Azelaic acid for the treatment of androgenic alopecia. To give a certified answer to your question is impossi ble: by all means, it all depends on the bio-availability of Azelaic acid how effective the product will be. If you would be able to make 100% of the amount of Azelaic acid bio-available you would need a concentration of 1,0-1,5% calculated on the basis of a gel-like preparation. 1. Add 2% ethoxydiglycol. This is a superb solvent for Azelaic acid and improves the dryness of the product when applied to the scalp. Ethoxydiglycol enables transdermal transport in the follicle, with a high degree of efficacy. For personal care & cosmetic products a maximum of ethoxydiglycol of 2,6% applies. This is not applicable for medical devices, given the “mode of action” of the medical device has been properly defined and that the consumer product is not subject to cytotoxicity. Ethoxydiglycol is supplied by Gattefosse as Transcutol CG. 2. Cytotoxicity can be suppressed by using 5% betaine (trimethylglycine), supplied by Dupont under the tradename Genencare OSMS BA. 3. It would properly better to use Zemea (INCI: propanediol; chemical name 1,3-propylene glycol). This product reduces the skin irritation induced by 1,2-propylkene glycol. Zemea is commercially made available by Dupont. 4. A system as applicable to your wishes is best thickened by 2-3% hydroxypropylcellulose (HPC). This polymer does not give a resident feel on the scalp. To prepare a gel the polymer shall first be dissolved in the final HPC before adding other products to be dissolved to avoid dissolution competition. HPC is commercially made available by Ashland as Klucel. 31. Question: Which pH is applicable for peelings? Answer: The pH of peelings is regulated by the SCCP opinion according to the used active ingredient. For example: - glycolic acid may be used safely at a level of up to 4% and a pH ≥ 3.8 - lactic acid up to a maximum level of 2.5% and a pH ≥ 5.0. But for Azelaic acid, considering is not a peeling active ingredient there are not indications by SCCP. In any case to have a stable product, the pH cannot be too low (>5). 32. Question: At what stage Azelaic acid should be added in a formulation to obtain the textu re of a product in cream or lotion? Answer: If predissolved in glycols or glycol based mixture, it can be added after the emulsioning step. In case of a w/o emulsion, Azelaic acid can be also added after the emulsioning step at a temperature of about 60°C (see SC005). In case of o/w emulsions it can be added in the oil phase once it is warmed (see SC001 and SC002 for more indications). The current system based on propylene glycol, glycerin & ethanol is rather resident on the scalp indeed, but it is a well-chosen sol vent for Azelaic acid. The system can be greatly improved using the following system:

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