Highlighting the Anti-Inflammatory Activity of Topical Gels Loaded with Meloxicam: The Role of Different Excipients and Absorption Promoters

Thermosensitive polyurethane (PU) hydrogels were prepared and loaded with meloxicam (MX), a nonsteroidal anti-inflammatory drug (NSAID). The role of different excipients, i.e., eucalyptus essential oil as well as poly(vinylpyrrolidone), poly(ethylene glycol) and their mixture, was highlighted. The sol–gel transition induced by temperature increase was evidenced by rheological measurements in oscillatory shear conditions. The viscoelastic behavior was investigated at 37 °C in various shear conditions, evidencing the network strength and stability of formulations. The structural recovery was monitored after applying high strain values, and the self-healing ability was revealed. Depending on the excipient, the gel samples loaded with MX release between 60% and 90% of the active substance. It was shown that the Fickian and chain relaxation contributions compete during MX release from PU-based hydrogels. In vitro anti-inflammatory activity was evaluated and discussed.