Microemulsion Microstructure Influences the Skin Delivery of an Hydrophilic Drug

作者：Naoui Wafa; Bolzinger Marie Alexandrine^*; Fenet Bernard; Pelletier Jocelyne; Valour Jean Pierre; Kalfat Rafik; Chevalier Yves

来源：Pharmaceutical Research, 2011, 28(7): 1683-1695.

DOI：10.1007/s11095-011-0404-y

• microemulsion
• microstructure
• percutaneous penetration
• phase diagram
• skin absorption

We aimed to investigate the influence of microemulsion nanoscale organization as either oil-in-water droplets, water-in-oil droplets, or bicontinuous structures on skin delivery of drugs assisted by microemulsions.
Three microemulsions of different microstructure, o/w, w/o, and bicontinuous at the skin temperature (32A degrees C), having the same oil and water contents and containing the same ingredients were selected using the Kahlweit fish phase diagrams method. The microemulsions are quaternary mixtures of the Polysorbate 21 (TweenA (R) 21) and Sorbitan monolaurate (SpanA (R) 20) surfactants, isononyl isononanoate oil and water. The microemulsion nanostructure was characterized by electrical conductivity, Pulsed Field Gradient Spin-Echo NMR and Small-Angle Neutron Scattering measurements. The Franz cell method was used to monitor skin absorption of caffeine loaded in microemulsions over 24 h exposure to excised pig skin.
Three microemulsions with the three structures were selected, keeping the same composition but the TweenA (R) 21/SpanA (R) 20 ratio. The transdermal flux of caffeine was in the order aqueous solution a parts per thousand w/o < bicontinuous < o/w microemulsion. The o/w microemulsion allows the permeation of 50% of the applied dose within 24 h.
The structure of microemulsions is of relevance for skin absorption. The water-continuous structures allow faster transport of hydrophilic drugs.

• 出版日期2011-7