title: Rheology as a Tool to Predict the Release of Alpha-Lipoic Acid from Emulsions Used for the Prevention of Skin Aging.
abstract: The availability of an active substance through the skin depends basically on two consecutive steps: the release of this substance from the vehicle and its subsequent permeation through the skin. Hence, studies on the specific properties of vehicles, such as their rheological behavior, are of great interest in the field of dermatological products. Recent studies have shown the influence of the rheological features of a vehicle on the release of drugs and active compounds from the formulation. In this context, the aim of this study was to evaluate the influence of the rheological features of two different emulsion formulations on the release of alpha-lipoic acid. Alpha-lipoic acid (ALA) was chosen for this study because of its antioxidant characteristics, which could be useful for the prevention of skin diseases and aging. The rheological and mechanical behavior and the in vitro release profile were assayed. The results showed that rheological features, such as viscosity, thixotropy, and compliance, strongly influenced the release of ALA from the emulsion and that the presence of a hydrophilic polymer in one of the emulsions was an important factor affecting the rheology and, therefore, the release of ALA.
authors.affiliation: Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, LaCos, Rodovia Araraquara Jau, Km 1, CEP 14800-850 Araraquara, SP, Brazil.
authors.forename: Vera Lucia Borges
authors.initials: VL
authors.lastname: Isaac
authors.affiliation: Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, LaCos, Rodovia Araraquara Jau, Km 1, CEP 14800-850 Araraquara, SP, Brazil; Centro Universitário de Araraquara (UNIARA), Rua Carlos Gomes 1338, 14801-340 Araraquara, SP, Brazil.
authors.forename: Bruna Galdorfini
authors.initials: BG
authors.lastname: Chiari-Andréo
authors.affiliation: Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Avenida Prof. Gama Pinto, 1649-003 Lisbon, Portugal.
authors.forename: Joana Marques
authors.initials: JM
authors.lastname: Marto
authors.affiliation: Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, LaCos, Rodovia Araraquara Jau, Km 1, CEP 14800-850 Araraquara, SP, Brazil.
authors.forename: Jemima Daniela Dias
authors.initials: JD
authors.lastname: Moraes
authors.affiliation: Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, LaCos, Rodovia Araraquara Jau, Km 1, CEP 14800-850 Araraquara, SP, Brazil.
authors.forename: Beatriz Alves
authors.initials: BA
authors.lastname: Leone
authors.affiliation: Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, LaCos, Rodovia Araraquara Jau, Km 1, CEP 14800-850 Araraquara, SP, Brazil.
authors.forename: Marcos Antonio
authors.initials: MA
authors.lastname: Corrêa
authors.affiliation: Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Avenida Prof. Gama Pinto, 1649-003 Lisbon, Portugal.
authors.forename: Helena Margarida
authors.initials: HM
authors.lastname: Ribeiro
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000627:therapeutic use; D004655:Emulsions / Q000737:chemistry / Q000627:therapeutic use; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D011108:Polymers / Q000737:chemistry; D012212:Rheology; D012867:Skin / Q000737:chemistry / Q000187:drug effects* / Q000473:pathology; D015595:Skin Aging / Q000187:drug effects* / Q000473:pathology; D008063:Thioctic Acid / Q000737:chemistry* / Q000627:therapeutic use
chemical_list: D000975:Antioxidants; D004655:Emulsions; D011108:Polymers; D008063:Thioctic Acid