Development and Characterization of a Nanophyton iliense-Based Gel for Topical Application

Background: Nanophyton iliense U.P. Pratov is a Central Asian halophytic plant whose phytochemical composition and suitability for pharmaceutical formulation remain insufficiently explored. This study evaluated the chemical profile, antioxidant activity, preliminary safety, and gel-forming potential of a hydroethanolic extract of N. iliense for topical application. Methods: The extract was characterized by GC–MS and HPLC. Total polyphenol content was determined, antioxidant activity was assessed using FRAP and DPPH assays, and preliminary cytotoxicity was evaluated using the Artemia salina lethality assay. Results: GC–MS and HPLC analyses showed that the extract contained both lipophilic constituents, including terpenoid and phytosterol-related compounds, and phenolic compounds such as catechin, epicatechin, and naringin. The total polyphenol content reached 485.05 mg GAE/L, exceeding the values obtained for the other plant extracts analyzed under the same conditions. The extract showed concentration-dependent antioxidant activity in both FRAP and DPPH assays. In the DPPH assay, radical scavenging activity increased up to 90.06% at 1.0 mg/mL, while FRAP results confirmed a strong reducing capacity. In the Artemia salina assay, no cytotoxic effect was observed at the tested concentrations. To assess pharmaceutical applicability, five gel formulations were prepared and compared. Gel No. 4, containing N. iliense extract, Lecigel, glycerin, Tween 80, benzyl alcohol, and purified water, showed the most suitable organoleptic and technological characteristics, including homogeneity, good spreadability, and absence of greasy residue. Conclusions: The obtained results indicate that N. iliense extract can be incorporated into a semi-solid formulation, while the extract itself demonstrates relevant in vitro antioxidant properties.