New alternatives to cosmetics preservation
This work was partially presented at the 7th Joint Meeting of AFRP, ASP, GA, PSE and SIF, Athens, Greece, and at the XIIIth COSMODERM Joint Meeting of ESCAD and the Hellenic Society of Dermatology and Venerology, Athens, Greece.
In recent years, there is a considerable interest in the development of preservative-free or self-preserving cosmetics. The aim of our work was to develop new cosmetic formulations by replacing chemical preservatives with ingredients with antimicrobial properties that are not legislated as preservatives according to Annex VI of Commission Directive 76/768/EEC. This paper describes the preservative efficacy of the well-known antimicrobial extracts of Lonicera caprifoleum and Lonicera japonica in combination with glyceryl caprylate and/or levulinic acid, p-anisic acid, and ethanol. We prepared a series of acidic (pH = 5.5) aqueous and O/W formulations, i.e., tonic lotion, shampoo, shower gel, conditioning cream, anticellulite cream, cleansing milk and peeling cream, containing (0.2% w/w) Lonicera extracts, alone in the case of tonic lotion and in combination with (1% w/w) glyceryl caprylate in the other products, and we performed challenge tests according to the European Pharmacopoeia procedures and criteria. Formulations such as shampoo, shower gel, and conditioning cream fulfilled criterion A, while tonic lotion, anticellulite cream, cleansing milk, and peeling cream fulfilled criterion B, in regard to contamination from A. niger. Furthermore, we evaluated the efficacy of the antimicrobial systems in two states of use: the intact product and after 3 weeks of consumer use. The results showed that A. niger was also detected during use by consumers in the products that satisfied only criterion B in challenge tests. The addition of antimicrobial fragrance ingredients such (≤0.3% w/w) levulinic acid or (0.1% w/w) p-anisic acid and/or (5% w/w) ethanol afforded products that met criterion A in challenge tests and were also microbiologically safe during use. The small quantity (5% w/w) of ethanol gave an important assistance in order to boost the self-preserving system and to produce stable and safe products.
Document Type: Abstract
Affiliations: 1: Laboratory of Cosmetology, Department of Aesthetics and Cosmetology, School of Health & Caring Professions, Technological Educational Institution, Ag. Spyridonos Str., 12210 Egaleo 2: Department of Pharmaceutical Technology, School of Pharmacy, University of Athens, Panepistimiopolis, 15771 Zografou, Athens, Greece
Publication date: October 1, 2010