Meloxicam-loaded nanocapsules have antinociceptive and antiedematogenic effects in acute models of nociception

AimsThe development of new treatments for inflammation and pain continues to be of high interest, since long-acting effect is critical for patients. The present study investigated whether the polymeric nanocapsules, a drug delivery system, have pharmacological effect on acute nociceptive and inflammatory models in mice.Main methodsSwiss mice (20-25 g) were previously pre-treated with meloxicam-loaded nanocapsules (M-NC) or free meloxicam (M-F) or suspension without drug (B-NC), at a dose of 5 mg/kg (per oral) at different times (0.5-120 h). Antinociceptive and antiedematogenic effects were evaluated by chemical (acetic acid-induced abdominal writhing, nociception and paw edema induced by formalin and glutamate, croton oil-induced ear edema) and thermal (tail immersion and hot-plate) tests.Key findingsM-NC reduced the licking time- and paw edema-induced by glutamate and formalin, while M-F did not have an effect. In the acetic acid-induced abdominal writhing and croton oil-induced ear edema, analysis of time-course revealed that M-NC showed a response more prolonged than M-F. In the hot-plate test, a thermal test, the time-course analysis indicated a similar increase in the latency response to thermal stimuli of M-NC and M-F, while in the tail-immersion test M-F had an effect at 0.5 h and M-NC at 24 h.SignificancePolymeric nanoparticles had antinociceptive, anti-inflammatory and antiedematogenic effects in the formalin and glutamate tests, and prolonged the effect in acetic acid and croton oil tests, but not in thermal tests, supporting the idea that the inflammatory process in tissues facilitates the vectoring of polymeric nanoparticles.