Efficacy and safety of a 0.05 % nanoencapsulated imiquimod hydrogel for the treatment of actinic cheilitis: Drug release analysis and clinical study

Actinic cheilitis (AC) is a lip disorder, with no standard treatment. Imiquimod (IMIQ) is an immunomodulator that treat precancerous lesions; however, its commercial form causes severe adverse effects. This study aimed to assess IMQ release from a chitosan hydrogel containing 0.05 % nanoencapsulated (NANO) imiquimod (IMIQ-0.05 %-NANO) and its efficacy in AC treatment. The hydrogels were prepared by incorporating chitosan into polymeric nanocapsules (NCimiq) loaded with IMQ, produced using the interfacial deposition of preformed polymer method. IMQ release was evaluated using automated Franz Cells. A triple-blind randomized controlled trial (49 subjects) compared the efficacy of: IMIQ-0.05 %-NANO, 5 % free imiquimod (IMIQ-5 %), 0.05 % free imiquimod (IMIQ-0.05 %), and placebo hydrogel. The IMIQ-NANO-0.05 % and IMIQ-5 % groups exhibited significantly higher rates of clinical improvement (p < 0.05); however, the IMIQ-5 % group experienced more adverse effects (92.3 % of subjects) compared to other groups (p < 0.05). In conclusion, in the studied sample, IMIQ-NANO-0.05 % was a safe and effective option to treat AC.