Novel antipsoriatic fluidized spanlastic nanovesicles: In vitro physicochemical characterization, ex vivo cutaneous retention and exploratory clinical therapeutic efficacy

Tazarotene (TAZ) is a topical synthetic retinoid used in psoriasis treatment, however, it is extremely lipophilic and exhibits skin irritation. Research is in a state of continuous advancement in the field of nanocarriers fabrication, and in this regard, we investigated the formulation of novel topically oriented nanovesicles; representing a combination of spanlastics and penetration enhancer vesicles, to be termed (fluidized-SNs). TAZ-loaded fluidized SNs were physicochemically characterized, tested for ex vivo cutaneous retention, and the selected formulation was compared with the marketed product Acnitaz (R) regarding clinical antipsoriatic activity. The selected fluidized-SNs enriched with 1% cineole exhibited high entrapment for TAZ (76.19%), suitable size and zeta potential of 241.5 +/- 5.68 nm and -36.10 +/- 2.50 mV respectively, and retaining of stability after refrigeration storage for one month. As hypothesized, cineole enriched fluidized-SNs exhibited remarkable TAZ deposition amounting to a total of 81.51% in the different skin layers. Upon clinical assessment, the presented formulation displayed superior traits compared to the marketed product, in terms of dermoscopic imaging, morphometric analysis of psoriatic lesions, and statistical analysis of PASI scores. Results confirmed that the prepared novel fluidized spanlastics formulation holds great promise for the treatment of psoriasis, and its benefit should futuristically be investigated in other topical diseases.