title: Hydrogel-thickened nanoemulsion system for topical delivery of lipophilic drugs.
abstract: In this work, a hydrogel-thickened nanoemulsion system (HTN) with powerful permeation ability, good stability and suitable viscosity was investigated for topical delivery of active molecules. HTN was prepared to deliver an oily mixture of 5% camphor, 5% menthol and 5% methyl salicylate for topical therapy of arthritis, minor joint and muscle pain using soybean oil as the oil phase, soybean lecithin, Tween 80 and poloxamer 407 as the surfactants, propylene glycol as the cosurfactant, carbomer 940 as a thickening agent. The HTN system was found to combine the o/w microstructure of nanoemulsion with the gel network of hydrogel and had a suitable viscosity of 133.2PaS. The system had small average diameters and good long-term stability. The abilities of HTN to deliver the high amounts of camphor, menthol and methyl salicylate were evaluated using the in vitro permeation studies. The permeation rates of camphor, menthol and methyl salicylate from the optimal HTN formulation were 138.0+/-6.5, 63.6+/-3.3, 53.8+/-3.2 microg cm(-2) h(-1) and showed the significant advantages over the control gel. The HTN with good stability and powerful permeation enhancing ability and suitable viscosity might be a promising prospective carrier for topical delivery of lipophilic drugs.
authors.affiliation: Institute of Materia Medica, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Mou
authors.forename: Huabing
authors.initials: H
authors.lastname: Chen
authors.forename: Danrong
authors.initials: D
authors.lastname: Du
authors.forename: Chengwen
authors.initials: C
authors.lastname: Mao
authors.forename: Jiangling
authors.initials: J
authors.lastname: Wan
authors.forename: Huibi
authors.initials: H
authors.lastname: Xu
authors.forename: Xiangliang
authors.initials: X
authors.lastname: Yang
mesh_terms: D000287:Administration, Topical; D016503:Drug Delivery Systems; D004355:Drug Stability; D004655:Emulsions; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000008:administration & dosage*; D053758:Nanoparticles; D010539:Permeability; D012995:Solubility
chemical_list: D004655:Emulsions; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate