Formulation and evaluation of ethosomal gel containing Nyctanthes arbor-tristis leaf extract using design of experiments for enhanced topical delivery

Background: Nyctanthes arbor-tristis (L.), generally known as Night Jasmine, is a medicinal plant renowned for its antimicrobial and antioxidant activities. Despite its traditional therapeutic use, there is limited scientific research on its detailed botanical characterization, phytochemical composition, and incorporation into advanced pharmaceutical formulations. This study aims to fill this gap by investigating the botanical and phytochemical profiles of N. arbor-tristis leaves and by developing optimized ethosomal gel formulations for enhanced topical drug delivery. Methodology: Comprehensive phytochemical screening revealed the existence of steroids, alkaloids, flavonoids, and tannins. Quality control parameters such as moisture content and ash values were evaluated. Ethosomal gels were prepared with phospholipids, cholesterol, and ethanol, and formulation optimization was performed using a Design of Experiments (DoE) approach. The developed formulations were systematically evaluated for particle size, polydispersity index, zeta potential, entrapment efficiency, and in vitro drug release profiles. Result and Discussion: Optimized formulations (EG-NAT-12 and EG-NAT-11) exhibited favorable nanoscale particle sizes (130.0 nm and 132.5 nm), low polydispersity indices (0.258 ± 0.027 and 0.274 ± 0.029), high negative zeta potentials (−23.5 mV to −24.0 mV), and high entrapment efficiencies (up to 89.8%). EG-NAT-12 demonstrated sustained drug release, with 84.0% released over 6 hrs. Stability testing confirmed the physical and chemical stability of the formulations over 45 days at both refrigerated and room temperatures. Conclusion: This study demonstrates the potential of Nyctanthes arbor-tristis ethosomal gels as effective topical drug delivery systems, integrating traditional herbal benefits with modern nanotechnology to enhance their efficacy.