Development of erlotinib-loaded nanotransferosomal gel for the topical treatment of ductal carcinoma<i> in situ</i>

<b>Aims: </b>This study was aimed to formulate erlotinib (ERL)-loaded transferosomal gel (ERL@TG) intended for topical application for the treatment of ductal carcinoma <i>in situ</i>. <b>Materials &amp; methods: </b>The optimized process involved a thin-film hydration method to generate ERL-loaded transferosomes (ERL@TFS), which was incorporated into a carbopol gel matrix to generate ERL@TG. The optimized formulation was characterized <i>in vitro </i>followed by cytotoxicity evaluation on MCF-7 breast cancer cell lines and acute toxicity and skin irritation studies was performed <i>in vivo</i>. <b>Results: </b>In a comparative assessment against plain ERL, ERL@TG displayed enhanced efficacy against MCF-7 cell lines, reflected in considerably lower IC50 values with an enhanced safety profile. <b>Conclusion: </b>Optimized ERL@TG was identified as a promising avenue for addressing ductal carcinoma <i>in situ </i>breast cancer.<b>Plain language summary: </b>Despite progress, breast cancer remains a significant cause of death. This study aimed to revolutionize the treatment of noninvasive ductal carcinoma <i>in situ</i>, a type of breast cancer, by developing a special gel that can be applied directly to the breast. The developed gel was in the nanoform, a ‘nanotransfersomal’ gel that contained erlotinib, a potent drug for breast cancer. To ensure its effectiveness, we evaluated the erlotinib-loaded transfersomal gel through various tests. The results confirmed that the gel was nano-sized and loaded with a high amount of erlotinib. Animal studies were conducted to check if the prepared gel caused any skin irritation and interestingly, there was no irritation observed on the animals’ skin. Furthermore, we treated breast cancer cells with the developed gel using a method called MTT assay and the results showed improved cell-killing activity in comparison to plain drug. In conclusion, this special gel represents a breakthrough in breast cancer treatment. It offers hope for better outcomes in the fight against this disease. This innovative approach involves directly applying the gel on the affected area topically to increase patient compliance and decreasing side effects of drugs. This could potentially transform ductal carcinoma <i>in situ </i>breast cancer treatment, bringing us closer to improved treatments and outcomes.