@article{scholars13279,
           title = {Ionic liquid-in-oil microemulsions prepared with biocompatible choline carboxylic acids for improving the transdermal delivery of a sparingly soluble drug},
          number = {4},
            note = {cited By 48},
          volume = {12},
             doi = {10.3390/pharmaceutics12040392},
         journal = {Pharmaceutics},
       publisher = {MDPI AG},
            year = {2020},
            issn = {19994923},
          author = {Islam, M. R. and Chowdhury, M. R. and Wakabayashi, R. and Kamiya, N. and Moniruzzaman, M. and Goto, M.},
        keywords = {aciclovir; carboxylic acid derivative; choline derivative; ionic liquid; oil; sorbitan laurate, animal tissue; Article; cell survival; controlled study; drug delivery system; Fourier transform infrared spectroscopy; human; human tissue; hydrophilicity; in vitro study; microemulsion; nonhuman; particle size; physical phase; pig; process optimization; survival rate; thermodynamics},
             url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85083987634&doi=10.3390\%2fpharmaceutics12040392&partnerID=40&md5=e2bc3b6e8b2de06b2ddb1eca70d4c676},
        abstract = {The transdermal delivery of sparingly soluble drugs is challenging due to of the need for a drug carrier. In the past few decades, ionic liquid (IL)-in-oil microemulsions (IL/O MEs) have been developed as potential carriers. By focusing on biocompatibility, we report on an IL/O ME that is designed to enhance the solubility and transdermal delivery of the sparingly soluble drug, acyclovir. The prepared MEs were composed of a hydrophilic IL (choline formate, choline lactate, or choline propionate) as the non-aqueous polar phase and a surface-active IL (choline oleate) as the surfactant in combination with sorbitan laurate in a continuous oil phase. The selected ILs were all biologically active ions. Optimized pseudo ternary phase diagrams indicated the MEs formed thermodynamically stable, spherically shaped, and nano-sized ({\ensuremath{<}}100 nm) droplets. An in vitro drug permeation study, using pig skin, showed the significantly enhanced permeation of acyclovir using the ME. A Fourier transform infrared spectroscopy study showed a reduction of the skin barrier function with the ME. Finally, a skin irritation study showed a high cell survival rate ({\ensuremath{>}}90) with the ME compared with Dulbecco{\^a}??s phosphate-buffered saline, indicates the biocompatibility of the ME. Therefore, we conclude that IL/O ME may be a promising nano-carrier for the transdermal delivery of sparingly soluble drugs. {\^A}{\copyright} 2020 by the authors. Licensee MDPI, Basel, Switzerland.}
}