Formulation and Preliminary Evaluation of a Piroxicam NanoEmulgel Containing Arnica and Clitoria ternatea Oils

Introduction: Oral and injectable formulations of piroxicam are associated with systemic adverse effects, including gastrointestinal toxicity and renal impairment. Topical nano-emulgel systems can mitigate these limitations by enabling localized, sustained drug delivery with reduced systemic exposure. Methods: Piroxicam nanoemulsions were formulated using high-speed homogenization followed by probe sonication and subsequently incorporated into a Carbopol 940 gel base. Four batches containing different concentrations of Arnica and Clitoria ternatea oils were prepared and evaluated for particle size, zeta potential, drug loading, encapsulation efficiency, rheological behavior, pH, spreadability, in vitro drug release, and stability. Results: Among all formulations, Batch 4 demonstrated optimal performance with a particle size of 195 nm, zeta potential of −43 mV, drug loading of 10.3%, and encapsulation efficiency of 92%. The formulation exhibited sustained release, achieving 89.2% piroxicam release over 12 hours. It also showed favorable physicochemical characteristics, including suitable pH (6.6), excellent spreadability (7.4 g·cm/sec), and absence of phase separation, indicating stability and skin compatibility. Discussion: Discussion: The incorporation of herbal oils enhanced the nanoemulsion stability and drug entrapment, likely contributing to prolonged drug release and improved topical performance. The nanoscale droplet size improved surface area and facilitated better permeation, while the negative zeta potential supported long-term dispersion stability. The synergistic anti-inflammatory properties of Arnica and Clitoria ternatea may further strengthen therapeutic outcomes. Overall, the optimized batch demonstrates a promising balance between efficacy, safety, and patient acceptability. Conclusion: The developed piroxicam nano-emulgel enriched with herbal oils offers a stable, effective, and patient-friendly topical alternative with enhanced drug release and reduced systemic side effects.