Efficient local delivery of FK506 using blocking patches in psoriasis

FK506 is a local drug that is commonly used in the treatment of psoriasis. Its clinical application, however, is limited by its transdermal drug delivery rate, the time-consuming, and the greasy therapy. In this study, which was inspired by local block injection used in the clinical treatment for keloid, a hyaluronic acid (HA) based system to transport FK506 into the skin to treat psoriasis, named blocking patch (BP) was developed. BP has a complete appearance, sufficient puncture strength, and is virtually non-irritating in vivo. By confocal fluorescence microscopy, BP loaded with FK506 (FK506-BP) showed satisfactory transdermal release ability in vivo. Further animal studies revealed that FK506-BP showed a good anti-inflammatory ability in the imiquimod (IMQ)-induced mouse psoriasis-like dermatitis and inhibited the activation of associated immune cells. This study indicates that BP as a novel delivery system, realizes an efficient local delivery of FK506 in psoriasis and holds great potential in transdermal delivery.