Liposphere mediated topical delivery of thymoquinone in the treatment of psoriasis.

Thymoquinone (TMQ) is reported with good anti-psoriatic activity; however, the hydrophobicity, poor aqueous solubility, light and pH sensitive nature of TMQ hinder its delivery to target site. To address these delivery challenges of TMQ, lipospheres were explored. The topical use of lipospheres offers an effective mean of penetration along with stability and scalability. TMQ lipospheres of particle size below 70 nm were prepared and evaluated. These lipospheres resulted in deeper skin penetration, slow release and skin compatibility. Anti-inflammatory and anti-psoriatic potential of lipospheres was determined using in vitro cell lines and imiquimod induced psoriatic plaque model. Cell lines studies indicated reduction in the level of nitric oxide and IL-2, IL-6, IL-1β, TNF-α, whereas in vivo results indicated improvement in the phenotypic, histopathological features and reduced level of IL-17 and TNF-α in psoriatic skin. These results suggest the potential of TMQ lipospheres in the management of psoriasis.