Design, Development, and Characterization of Imiquimod-Loaded Chitosan Films for Topical Delivery


Aldara™ (5% w/w imiquimod) topical cream is approved by the US FDA for the treatment of superficial basal cell carcinoma. However, the cream formulation suffers from dose variability, low drug availability due to the incomplete release, and poor patient compliance. To achieve sustained and complete release of imiquimod, chitosan films were prepared by casting using propylene glycol as a plasticizer. Chitosan films had appropriate physicochemical characteristics for wound dressing and excellent content uniformity and maintained the original physical form of imiquimod. Films were capable of releasing a defined dose of imiquimod over a period of 7 days. The bioactivity of imiquimod was not affected by its entrapment in chitosan matrix as indicated by the results of in vitro growth inhibition assay. In addition, the film formulation showed significantly (p ˂ 0.05) higher drug accumulation in the skin when compared to commercial cream formulation.

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The authors would like to thank Hanna Iaizzo and Mamta Kapoor for conducting the preliminary studies. The mechanical tests were performed at the Characterization Facility, University of Minnesota, Minneapolis, MN.

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Correspondence to Swayam Prabha.

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Layek, B., Rahman Nirzhor, S.S., Rathi, S. et al. Design, Development, and Characterization of Imiquimod-Loaded Chitosan Films for Topical Delivery. AAPS PharmSciTech 20, 58 (2019).

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Key Words

  • chitosan
  • imiquimod
  • basal cell carcinoma
  • film formulation
  • topical drug delivery