Tocopheryl acetate nanoemulsions stabilized with lipid-polymer hybrid emulsifiers for effective skin delivery.
Tocopheryl acetate is used as the oil component of nanoemulsions using a mixture of unsaturated phospholipids and polyethylene oxide-block-poly(ε-caprolactone) (PEO-b-PCL). This study investigates the effects of the lipid-polymer composition on the size and surface charge of nanoemulsions, microviscosity of the interfacial layer, and skin absorption of tocopheryl acetate. The lipid-polymer hybrid system exhibits excellent colloidal dispersion stability, which is comparable to that of polymer-based nanoemulsions. If lipids are used as emulsifiers, nanoemulsions show poor dispersion stability despite a good skin absorption enhancing effect. The amount of tocopheryl acetate absorbed by the skin increases with an increased lipid-to-polymer ratio, as determined using the hairless guinea pig skin loaded in a Franz-type diffusion cell. An 8:2 (w/w) mixture of unsaturated phospholipids and PEO-b-PCL exhibits the most efficient delivery of tocopheryl acetate into the skin. Our results show that tocopheryl acetate is absorbed almost twice as fast by the lipid-polymer hybrid system than the nanoemulsions stabilized with PEO-b-PCL. This study suggests that the lipid-polymer hybrid system can be used as an effective means of optimizing nanoemulsions in terms of dispersion stability and skin delivery capability.
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon, Republic of Korea. yoonsung@kaist.ac.kr
Yoon Sung
YS
Nam
Jin-Woong
JW
Kim
Jaeyoon
J
Park
Jongwon
J
Shim
Jong Suk
JS
Lee
Sang Hoon
SH
Han
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D015194:Diffusion Chambers, Culture; D004337:Drug Carriers / Q000138:chemical synthesis / Q000737:chemistry*; D045703:Emulsifying Agents / Q000737:chemistry; D004655:Emulsions; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007700:Kinetics; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D010713:Phosphatidylcholines / Q000737:chemistry*; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry*; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption; D055672:Static Electricity; D013499:Surface Properties; D024505:Tocopherols / Q000737:chemistry / Q000493:pharmacokinetics*; D014783:Viscosity
D004337:Drug Carriers; D045703:Emulsifying Agents; D004655:Emulsions; D010713:Phosphatidylcholines; D011091:Polyesters; C458722:polyethylene oxide-polycaprolactone copolymer; D024505:Tocopherols