Development of nanoemulsions for topical delivery of vitamin K1

Vitamin K1 (VK1) is a natural and lipophilic compound currently used in dermatological formulations. In this work, nanoemulsions containing VK1 have been proposed to overcome some issues associated to semisolid VK1-incorporating formulations. The study has been focused on the design of a lipid-free aqueous formulation, easy to prepare and with low cost of production. Thus, a simply protocol, using a low-energy method, has been used to spontaneously form the nanoemulsions. The nanoemulsion composition has been optimized to improve its physical stability during storage in different conditions. Then, the possibility to administer VK1-containing nanoemulsions by nebulization without significant alteration of the formulation was tested. Moreover, the VK1 accumulation into the skin layers have been evaluated through permeation experiments on Franz cells, ATR-FITR analysis, confocal laser scanning microscopy (CLSM) observations, and high performance liquid chromatography (HPLC) analysis. The study demonstrated that NEs represent an interesting option for the commercial development of an aqueous spray formulation for the topical delivery of VK1.