title: Chemical stability and SPF determination of Pothomorphe umbellata extract gel and photostability of 4-nerolidylcathecol.
abstract: Due to its antioxidant and photoprotective properties, Pothomorphe umbellata is a promising candidate for use in cosmetic and pharmaceutical formulations. These properties arise from the presence of 4-nerolidylcathecol (4-NC), a polyphenolic compound isolated from P. umbellata roots. This study investigates its photostability properties, as well as the chemical and the in vitro sun protection factor (SPF) of P. umbellata root extract in a gel formulation. A high performance liquid chromatography method was used to evaluate the chemical stability using 4-NC as marker at 5, 25 and 45 degrees C for 103 days. The photostability and the sun protection factor were analyzed by ultraviolet (UV) spectophotometry using samples irradiated with UVB lamp. No significant difference of the 4-NC concentration was found in formulations stored at 5 and 25 degrees C. All samples stored at 45 degrees C, however, showed degradation of gel structure. After 2h of UVB exposure, there was no change in the absorption profile of 4-NC. The sun protection factor of P. umbellata root extract gel to final concentration of 0.1% 4-NC was not expressive (SPF=3.35+/-0.02), suggesting the predominance of its antioxidant activity.
authors.affiliation: Departamento de Análises Clínicas e Toxicológicas, School of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 580, 05508-000 São Paulo, SP, Brazil. vavitoria@usp.br
authors.forename: Vanessa V
authors.initials: VV
authors.lastname: da Silva
authors.forename: Cristina D
authors.initials: CD
authors.lastname: Ropke
authors.forename: Rebeca L
authors.initials: RL
authors.lastname: de Almeida
authors.forename: Denise V
authors.initials: DV
authors.lastname: Miranda
authors.forename: Clarissa Z
authors.initials: CZ
authors.lastname: Kera
authors.forename: Diogo P
authors.initials: DP
authors.lastname: Rivelli
authors.forename: Tânia C H
authors.initials: TC
authors.lastname: Sawada
authors.forename: Silvia B M
authors.initials: SB
authors.lastname: Barros
mesh_terms: D000180:Acrylic Resins; D002396:Catechols / Q000032:analysis; D004355:Drug Stability; D005782:Gels; D010777:Photochemistry; D026321:Piperaceae / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry* / Q000528:radiation effects; D018517:Plant Roots / Q000737:chemistry; D013053:Spectrophotometry; D013473:Sunscreening Agents / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D013696:Temperature; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: C110583:4-nerolidylcatechol; D000180:Acrylic Resins; D002396:Catechols; D005782:Gels; D010936:Plant Extracts; D013473:Sunscreening Agents; C006903:carbopol 940