title: Benefits of combinations of vitamin A, C and E derivatives in the stability of cosmetic formulations.
abstract: Chemically stable ester derivatives of vitamins A, C and E have become a focus of interest for their role in the satisfactory results in skin aging treatments. Accordingly, the aim of this study was to evaluate the physical and chemical stability of a cosmetic formulation containing 1% retinyl palmitate, ascorbyl tetraisopalmitate and tocopheryl acetate, alone or in combination. In the studies of physical stability, a Brookfield rheometer was used to determine rheological behavior of formulations containing the vitamins. Chemical stability was determined by HPLC on a Shimadzu system with UV detection. Results showed that formulations had pseudoplastic behavior and that vitamins did not alter their apparent viscosity and thixotropy. In the chemical stability studies, first-order reaction equations were used for determinations of the shelf-life of vitamins derivatives considering a remaining concentration of 85%. Combined vitamins in a single formulation had a slightly lower degradation rate as compared to different preparations containing only one of the vitamins. Considering that many cosmetic formulations contain vitamin combinations it is suggested that the present study may contribute to the development of more stable formulations containing liposoluble vitamins.
authors.affiliation: Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo, Av do Cafe s/n, Monte Alegre, Ribeirao Preto 14040-903, SP, Brazil.
authors.forename: Mirela Donato
authors.initials: MD
authors.lastname: Gianeti
authors.forename: Lorena Rigo
authors.initials: LR
authors.lastname: Gaspar
authors.forename: Flávio Bueno de
authors.initials: FB
authors.lastname: Camargo
authors.forename: Patrícia Maria Berardo Gonçalves Maia
authors.initials: PM
authors.lastname: Campos
mesh_terms: D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods; D003358:Cosmetics / Q000737:chemistry*; D004224:Diterpenes; D004355:Drug Stability; D000084562:Retinyl Esters; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000737:chemistry; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D003358:Cosmetics; D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; D014810:Vitamin E; C014794:retinol palmitate; D001205:Ascorbic Acid