Baricitinib-loaded separable microneedle array patch (S-MAP) based on hyaluronic acid for alopecia areata therapy.

Separable and dissolvable microneedle array patch based primarily on hyaluronic acid is designed for the topical delivery of baricitinib in alopecia areata (AA) therapy. Locoregional application of a separable microneedle array patch (S-MAP) may avoid the systemic side effects of oral administration and can be administered without pain compared with typical intradermal injections. Baricitinib (which has poor aqueous solubility) is evenly suspended with sodium carboxymethylcellulose. Subsequently, the mixture is blended with other pharmaceutical excipients, such as hyaluronic acid, sucrose, and Tween 80, to fabricate the S-MAP. Crystalline baricitinib transformed into an amorphous state during the drying process, which may have contributed to complete drug dissolution in the aqueous buffer within 60 min. Proper insertion of a baricitinib-loaded S-MAP into porcine skin tissue and mouse skin is demonstrated using optical coherence tomography and near-infrared fluorescence imaging, respectively. Topical administration of the baricitinib-loaded S-MAP system to the AA lesion of mouse models resulted in significantly higher hair growth compared with the control group (S-MAP: 82 % vs. control: 31 %, p < 0.05). These findings suggest that the baricitinib S-MAP system can be used efficiently and safely, while affording pain-free and self-medication properties, for the AA therapy.