title: Moisturizing effect of cosmetic formulations containing Aloe vera extract in different concentrations assessed by skin bioengineering techniques.
abstract: OBJECTIVE
  The polysaccharide-rich composition of Aloe vera extracts (Aloe barbadensis Miller), often used in cosmetic formulations, may impart moisturizing properties to the product. The aim of this study was to evaluate the effect of cosmetic formulations containing different concentrations of freeze-dried Aloe vera extract on skin hydration, after a single and a 1- and 2-week period of application, by using skin bioengineering techniques.
  
  
  METHODS
  Stable formulations containing 5% (w/w) of a trilaureth-4 phosphate-based blend were supplemented with 0.10%, 0.25% or 0.50% (w/w) of freeze-dried Aloe vera extract and applied to the volar forearm of 20 female subjects. Skin conditions in terms of the water content of the stratum corneum and of transepidermal water loss (TEWL) (Corneometer CM 825 and Tewameter TM 210) were analysed before and after a single and 1- and 2-week period of daily application.
  
  
  RESULTS
  After a single application, only formulations supplemented with 0.25% and 0.50% (w/w) of Aloe vera extract increased the water content of the stratum corneum, while after the 2-week period application, all formulations containing the extract (0.10%, 0.25% and 0.50%) had the same effect, in both cases as compared with the vehicle. TEWL was not modified after a single and after 1- and 2-week period of application, when compared with the vehicle.
  
  
  CONCLUSIONS
  Our results show that freeze-dried Aloe vera extract is a natural effective ingredient for improving skin hydration, possibly through a humectant mechanism. Consequently, it may be used in moisturizing cosmetic formulations and also as a complement in the treatment of dry skin.
authors.affiliation: Laboratory of Cosmetic Technology, Faculdade de Ciencias Farmaceuticas de Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Susi Elaine
authors.initials: SE
authors.lastname: Dal'Belo
authors.forename: Lorena Rigo
authors.initials: LR
authors.lastname: Gaspar
authors.forename: Patrícia Maria Berardo Gonçalves
authors.initials: PM
authors.lastname: Maia Campos
mesh_terms: D000328:Adult; D000504:Aloe / Q000737:chemistry*; D001698:Biomedical Engineering / Q000379:methods; D001834:Body Water / Q000378:metabolism*; D003358:Cosmetics / Q000008:administration & dosage / Q000737:chemistry* / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004817:Epidermis / Q000378:metabolism; D005260:Female; D005612:Freeze Drying; D006801:Humans; D009994:Osmolar Concentration; D010936:Plant Extracts / Q000008:administration & dosage*; D012867:Skin / Q000187:drug effects* / Q000378:metabolism*; D014870:Water Loss, Insensible / Q000187:drug effects
chemical_list: D003358:Cosmetics; D010936:Plant Extracts