Evaluation of Olive Oil-Based Formulations Loaded with Baricitinib for Topical Treatment of Alopecia Areata

<b>Background:</b> Alopecia areata is an autoimmune disorder that causes hair loss in clumps about the size and shape of a quarter. The estimated prevalence of the disorder is approximately 1 in 1000 people, with a lifetime risk of approximately 2 percent. One of the systemic therapies for alopecia areata consists of the use of glucocorticoids or immunosuppressants. <b>Methods:</b> Baricitinib (BCT) is a Janus kinase (JAK) 1 and 2 selective inhibitor used as an immunosuppressant drug. In this study, three olive oil BCT formulations (Oil A, Oil B, and Oil C, which differ in their content in squalene, tocopherol, tyrosol, and hydroxytyrosol) have been developed for topical delivery. The formulations were physicochemically characterized and the in vitro drug release and ex vivo permeation through human skin tissues were assessed. <b>Results:</b> The results showed nearly identical viscosity across all three formulations, exhibiting Newtonian behavior. The mathematical modeling used to describe the drug release profiles was the one-site binding hyperbola for all formulations. Oil-based formulations showed a slow BCT penetration into human skin. Skin integrity remained intact during the experiments, with no signs of irritation or alterations observed. In addition, all the formulations proved their efficacy in vivo. <b>Conclusions:</b> Among the formulations, Oil A demonstrated the highest ability retention capacity (<i>Q</i>_r = 1875 ± 124.32 ng/cm²) in the skin, making it an excellent candidate for further investigation in the treatment of alopecia areata.