Objective: The present investigation aimed to prepare a smilax china loaded nanoemulsion using tween 80 as a surfactant and propylene glycol as a co-surfactant. Formulation of such drugs in nanoparticulate drug delivery will be advantageous for reducing dosing frequency, longer residence time, improved permeation, and patient compliance.

Methods: High-speed homogenization method. The smilax china oil was prepared by collecting the extract of smilax china leaves into the coconut oil and then used as a solvent. The authentication studies of smilax china and coconut oil were evaluated for their organoleptic and physicochemical characteristics. The quantitative estimation and pre-formulation study of quercetin was carried out which has major anti-psoriatic properties. Surfactant and co-surfactant were selected and the solubility studies of oil and Surfactants were done. The nanoemulsion was characterized by particle size, polydispersity index, zeta potential, and entrapment efficiency (%).

Results: This nanoemulsion provides the particle size and entrapment efficiency range between 80.52 to 89.78 nm and 68.66 to 70.16 % respectively. Batch SC1 showed the lowest particle size, PDI, and optimized drug entrapment effectiveness (%), indicating good particle size consistency within the remaining formulation batches. The optimized formulation SC 1 was found to be stable for 90 d.

Conclusion: The formulated nanoemulsion showed significant antipsoriasis activity due to the presence of quercetin which has a rhetorical yield of 1.066 mg per 5 gm powder of smilax china leaves. Formulated smilax china-loaded nanoemulsion, has the potential as an effective antipsoriasis agent with a good spreading property with faster absorption which is beneficial for reducing drug concentration with maximum therapeutic effect.