Acne vulgaris is the most common inflammatory skin disorder and jeopardizes seriously the facial impression of a person. Development of acne involves a complex relation among several causes. Treatment and prevention success can be archived by affecting the main contributors positively like Proprionibacterium acnes or lipid oxidation leading to inflammatory reactions and follicular keratinization. Vitamin C tends to break down in cosmetic formulations resulting in a brownish discoloration. Sodium ascorbyl phosphate (SAP) represents a stable precursor of vitamin C that ensures a constant delivery of vitamin C into the skin.
We were able to show that 1% SAP has a strong antimicrobial effect with a log reduction of 5 after 8 h on P. acnes in a time-kill study. Further on in a human in vivo study with 20 subjects an SAP O/W formulation significantly prevents the UVA-induced sebum oxidation up to 40%. Finally, we performed an open in vivo study with 60 subjects with a 5% SAP lotion over 12 weeks. The efficacy ranked as excellent and good of SAP was 76.9%, which was superior compared with a widely prescribed acne treatment. In conclusion, these data show that SAP is efficient in the prevention and treatment of acne vulgaris. SAP can be used in a non-antibiotic and effective treatment or co-treatment of acne with no side effects, which makes it particularly attractive for cosmetic purposes.