Design and characterization of wheatgrass extract Nanoemulsion-Based hydrogel for enhanced dermal targeting in skin cancer

Abstract

Wheatgrass-extracted nanoemulsion (NE) and nanoemulgel (NEG) were developed and tested to improve topical delivery and dermal therapeutic efficacy. The wheatgrass extract’s solubility and emulsification efficiency determined the excipients: orange oil, Tween 80, and Carbitol. The pseudoternary phase diagram showed that the 2:1 Smix (Tween 80: Carbitol) ratio produced the largest monophasic nanoemulsion area. F3, the optimised formulation, had nanodroplets of 121.48 nm, a low polydispersity index (PDI) of 0.251, and a negative stability zeta potential of -26.29 mV. The formulation was thermodynamically stable under heating/cooling cycles, centrifugation, and freeze/thaw tests. The nanoemulgel containing Carbopol 940 exhibited favourable rheological and physicochemical properties, including a pH of 6.48 ± 0.12, a viscosity of 4870 ± 25 cP, good spreadability, and homogeneity. Drug content was particularly high at 96.38%. The drug form NA released 95.11% at 24 h, compared to 86.42% for NA. The test NEG penetrated excised skin with 95.08% permeation after 24 h and increased skin deposition (1041.49 µg/cm²) compared to standard gel formulations. Cytotoxicity studies on A431 skin carcinoma cells showed the negative test formulation was safe, with cell viability exceeding 50% and NEG IC₅₀ greater than 5624 µg/mL. These findings suggest that the wheatgrass nanoemulgel may be a safe and effective dermally directed therapeutic delivery system.