Title : Glycyrrhetic acid-loaded microemulsion-based konjac gel for psoriasis: Enhanced topical delivery and immunomodulatory effects
Abstract:
Psoriasis is a chronic inflammatory skin disorder caused by an immune system imbalance and the excessive production of pro-inflammatory cytokines, which in turn demands the development of potent and safe topical treatments. Glycyrrhetic acid (GA) is a triterpenoid component of licorice root, which shows very strong anti-inflammatory activity, but the efficacy of GA in clinical phases has been hindered by its low water solubility and poor ability to penetrate the skin. The current research investigates a microemulsion (MEs)-based approach to eliminating these problems and increasing the topical administration of GA. MEs containing GA were prepared with Capryol 90 as an oil phase, Cremophor/Labrasol, and Transcutol as a Smix and then incorporated into a gel matrix made of konjac glucomannan and Carbopol 940 to increase retention due to the low viscosity of MEs. Several experiments were carried out on the formulation, and then it was characterised with physicochemical properties, rheology, and stability. The formulation was further tested for in vitro release, ex vivo permeation, and in vivo anti-psoriatic effects using an imiquimod-induced mouse model. The formulated system exhibited very small droplet size (25.07±2.18 nm), a narrow particle size distribution, and suitable topical features. The in vivo studies showed the ability to counteract the pathological features of psoriasis, which was also evidenced by the reparative changes in the skin, decreased level of skin inflammatory markers, and lessening of the systemic immune response. The study demonstrated that MEs-based gels are a feasible and efficacious strategy to augment the topical delivery of hydrophobic plant phytoconstituents for the therapy of psoriasis.
Keywords: Glycyrrhetic acid, Inflammation, Psoriasis, Microemulsion, Konjac Glucomannan.
