title: Effect of vehicles on topical application of aloe vera and arnica montana components.
abstract: In this study two types of gels and microemulsions are investigated for their ability to dissolve, release, and induce the permeation of helenalin, a flavonoid responsible for the anti-inflammatory activity of arnica montana extract, and aloin, an anthrone-C-glucosyls with antibacterial activity present in aloe vera extract. The release of these agents from each vehicle was followed by HPLC, and transcutaneous permeation was examined using a modified Franz cell and a porcine skin membrane. The study showed that a microemulsion can be a good vehicle to increase the permeation of helenalin, while the gel formulation, containing Sepigel 305, proved able to reduce the release and permeation of aloin, with a consequent activity limited to the surface of application, without any permeation. This is in accordance with the necessity to avoid this process, since human skin fibroblasts can metabolize absorbed aloin into a structurally related compound that increases the sensitivity of skin to ultraviolet light.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università di Bologna, Bologna, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Bergamante
authors.forename: Gian Carlo
authors.initials: GC
authors.lastname: Ceschel
authors.forename: Sergio
authors.initials: S
authors.lastname: Marazzita
authors.forename: Celestino
authors.initials: C
authors.lastname: Ronchi
authors.forename: Adamo
authors.initials: A
authors.lastname: Fini
mesh_terms: D000279:Administration, Cutaneous; D000504:Aloe / Q000737:chemistry; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000493:pharmacokinetics; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry* / Q000302:isolation & purification / Q000493:pharmacokinetics; D018650:Arnica / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid; D004058:Diffusion; D004642:Emodin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000493:pharmacokinetics; D004655:Emulsions / Q000737:chemistry; D005079:Excipients / Q000737:chemistry; D005782:Gels / Q000737:chemistry; D006801:Humans; D010539:Permeability; D014677:Pharmaceutical Vehicles / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000493:pharmacokinetics; D012717:Sesquiterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000493:pharmacokinetics; D045789:Sesquiterpenes, Guaiane; D012869:Skin Absorption; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D004655:Emulsions; D005079:Excipients; D005782:Gels; D014677:Pharmaceutical Vehicles; D010936:Plant Extracts; D012717:Sesquiterpenes; D045789:Sesquiterpenes, Guaiane; C001329:helenalin; D004642:Emodin; C006457:alloin