A cutback in Imiquimod cutaneous toxicity; comparative cutaneous toxicity analysis of Imiquimod nanotransethosomal gel with 5% marketed cream on the BALB/c mice

Herein, Imiquimod (IMQ) was incorporated in nanotransethosomes (nTES) to develop the IMQ-nTES nano-drug delivery system. IMQ-nTES was optimized using 2(3) factorial design. The optimized formulation was expressed with a particle size of 192.4 ± 1.60 nm, Poly-dispersibility of 0.115 ± 0.008, and IMQ percent entrapment efficiency of 91.05 ± 3.22%. Smooth and round morphology of IMQ-nTES vesicles was confirmed by TEM micrographs. Moreover, FTIR results have shown drug-excipient compatibility. The IMQ-nTES was laden inside the low molecular weight chitosan gel, which exhibited easy application, spreadability and no irritation to the applied skin. The release pattern has clearly exhibited improved dissolution properties of IMQ with the provision of the sustain release pattern. Higher IMQ content was deposited in deeper epidermis and dermis with IMQ-nTES gel, in contrast to ALDARA. In vivo, comparative toxicity study on BALB/c mice has shown significantly reduced (p < 0.001) psoriatic area severity index (PASI) score and less increment in ear thickness. Epidermal hyperplasia was an obvious finding with ALDARA which was, providentially, minimal in IMQ-nTES gel-treated skin. FTIR analysis of skin tissue has shown an enhancement of lipid and protein content in the ALDARA group, however, in the IMQ-nTES group no such change was observed. With ALDARA application, CD4(+) T-cells and constitutive NF-κβ expression were significantly elevated, in comparison to the IMQ-nTES gel treated group. Moreover, the adequate expression of IFN-γ and cytotoxic CD8(+) T-cells were suggesting the preserved IMQ efficacy with IMQ-nTES gel. Quantification of cutaneous as well as systemic inflammatory markers has also suggested the reduced psoriatic potential of IMQ-nTES gel. In essence, IMQ-nTES gel can be a suitable alternative to ALDARA owing to its better safety profile.