title: Hydrogel-thickened microemulsion for topical administration of drug molecule at an extremely low concentration.
abstract: In this work, a hydrogel-thickened microemulsion (HTM) was investigated for delivering an extremely low concentration of drug molecule. The pseudo-ternary phase diagrams were constructed using isopropyl myristate (IPM), Tween 80, propylene glycol and water. The various HTM were prepared and characterized. We described that HTM has the combination of o/w microstructure of microemulsion and the three-dimensional gel network of hydrogel in continuous phase using transmission electron microscope. The stability tests showed that HTM had good stability. The influence of the addition of hydrogel into microemulsions on the viscosity and permeation ability is investigated. The abilities of HTM to deliver an extremely low concentration of triptolide as a model drug were evaluated using the in vitro permeation studies. The permeation rates of triptolide from various HTM were 2.2-3.6 times over that from the control hydrogel. The addition of 2% menthol into HTM consisting of 3% IPM, 30% Tween 80, 15% propylene glycol, 0.75% carbomer 940 resulted in the highest permeation rate of 0.105+/-0.006microcm(-2)h(-1), which was 5.8 times over control gel. The powerful permeation enhancing ability of HTM with a suitable viscosity makes it promising alternative carrier for transdermal administration of drug molecule at an extremely low concentration.
authors.affiliation: College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, China.
authors.forename: Huabing
authors.initials: H
authors.lastname: Chen
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Mou
authors.forename: Danrong
authors.initials: D
authors.lastname: Du
authors.forename: Xueling
authors.initials: X
authors.lastname: Chang
authors.forename: Dandan
authors.initials: D
authors.lastname: Zhu
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Huibi
authors.initials: H
authors.lastname: Xu
authors.forename: Xiangliang
authors.initials: X
authors.lastname: Yang
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D002626:Chemistry, Pharmaceutical; D015194:Diffusion Chambers, Culture; D004224:Diterpenes / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D004337:Drug Carriers; D004339:Drug Compounding; D004655:Emulsions; D004852:Epoxy Compounds / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D020100:Hydrogels; D008297:Male; D008610:Menthol / Q000494:pharmacology; D051379:Mice; D046529:Microscopy, Electron, Transmission; D009226:Myristates / Q000737:chemistry* / Q000633:toxicity; D010316:Particle Size; D010539:Permeability; D044367:Phase Transition; D010616:Phenanthrenes / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D011136:Polysorbates / Q000737:chemistry; D019946:Propylene Glycol / Q000737:chemistry* / Q000633:toxicity; D011817:Rabbits; D012867:Skin / Q000187:drug effects / Q000378:metabolism*; D012869:Skin Absorption / Q000187:drug effects; D012871:Skin Diseases / Q000139:chemically induced; D023422:Skin Irritancy Tests; D013678:Technology, Pharmaceutical / Q000379:methods; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D004224:Diterpenes; D004337:Drug Carriers; D004655:Emulsions; D004852:Epoxy Compounds; D020100:Hydrogels; D009226:Myristates; D010616:Phenanthrenes; D011136:Polysorbates; D014867:Water; C008205:isopropyl myristate; D008610:Menthol; C001899:triptolide; D019946:Propylene Glycol