title: Bicontinuous water-AOT/Tween85-isopropyl myristate microemulsion: a new vehicle for transdermal delivery of cyclosporin A.
abstract: The purpose of this study was to investigate the influence of structure and composition of microemulsions (AOT/Tween85/isopropyl myristate/water) on their transdermal delivery potential of a lipophilic model drug (Cyclosporin A), and to compare the drug delivery potential of microemulsion to the suspension of drug in normal saline containing 20% ethanol. Their type and structure were examined by measuring surface tension, density, viscometry, and electric conductivity; the degree of agreement between the techniques was assessed. Transdermal flux of Cyclosporin A through rat skin was determined in vitro using Franz-type diffusion cells. Results of conducting, viscosity, and surface tension measurement confirmed the prediction transition to a bicontinuous structure. The microemulsions increased transdermal drug delivery of Cyclosporin A up to 10 times compared to the suspension. The increased transdermal delivery was found to be due mainly to water concentration and appeared to be dependent on the structure of the microemulsions.
authors.affiliation: School of Pharmaceutics, Pharmaceutical University of Shenyang, Shenyang 110016, People's Republic of China.
authors.forename: Hongzhuo
authors.initials: H
authors.lastname: Liu
authors.forename: Sanming
authors.initials: S
authors.lastname: Li
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Han
authors.forename: Yang
authors.initials: Y
authors.lastname: Dong
mesh_terms: D000279:Administration, Cutaneous; D000465:Algorithms; D000818:Animals; D055598:Chemical Phenomena; D002626:Chemistry, Pharmaceutical; D002627:Chemistry, Physical; D016572:Cyclosporine / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry*; D004553:Electric Conductivity; D004655:Emulsions / Q000737:chemistry; D005079:Excipients / Q000737:chemistry*; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry*; D066298:In Vitro Techniques; D007509:Irritants; D009226:Myristates / Q000737:chemistry*; D011136:Polysorbates / Q000737:chemistry*; D011817:Rabbits; D051381:Rats; D012869:Skin Absorption; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*; D014783:Viscosity; D014867:Water
chemical_list: D004655:Emulsions; D005079:Excipients; D007166:Immunosuppressive Agents; D007509:Irritants; D009226:Myristates; D011136:Polysorbates; D013501:Surface-Active Agents; D014867:Water; C008205:isopropyl myristate; D016572:Cyclosporine