Formulation Development, Statistical Optimization, In Vitro and In Vivo Evaluation of Etoricoxib-Loaded Eucalyptus Oil-Based Nanoemulgel for Topical Delivery

Pain is a common distress in chronic inflammatory diseases, and etoricoxib (ETB) frequently used its management. It possesses fewer adverse effects when compared with other non-steroidal anti-inflammatory drugs (NSAIDs). In the present study, ETB-loaded nanoemulsion (ETB-NE) was formulated optimized. Eucalyptus oil, Tween 20, PEG 200 were chosen as surfactant, co-surfactant, respectively. The formulation optimized using Box–Behnken design. ETB-NE contained Smix, water concentrations of 11.5, 38, 50% had droplet size, polydispersity index, zeta potential values 179.6 ± 4.21 nm, 0.373 0.02, ?10.9 1.01 mV, sample passed thermodynamic stability dispersibility tests. Transmission electron microscopy confirmed spherical morphology NE droplets. showed biphasic drug release pattern released 85.3 1.8% ETB at 12 h. into gel (NEG) by 1% carbopol 934. ETB-NEG characterized for pH, viscosity, content, percentage entrapment efficiency. During vitro permeation studies, apparent permeability coefficient value 0.072 cm?2 h?1 ETB-NEG, while it only 0.047 gel. skin histopathology study results that non-irritant safe topical use. maximum possible analgesia observed significantly high (p < 0.05) 47.09% after 60 min. Similarly, formalin-induced acute pain rats also demonstrated higher % inhibition 37.37 5.9 51.95 4.4 late phases, Further, 78.4 3.5% 8 h vivo testing rat paw edema method. found to enhance analgesic ETB. could stimulate further studies this area establishing clinically successful NEG