Topical delivery of nanoemulsions for skin cancer treatment

Skin cancer chemotherapeutics often lead to the development of severe cytotoxicity, compelling the development of novel delivery systems to not only enhance therapeutic efficacy but also minimize side effects and improve patient compliance. In recent years, topical nanoemulsions have emerged as powerful tools in the field of skin cancer therapeutic management. This review delves into the potential of these innovative formulations to revolutionize the treatment of skin malignancies, due to their unique properties, having relevant advantages, such as allowing high drug strength, skin drug permeation and retention enhancement, biocompatibility, and controlled release capacity. Despite the skin's formidable permeability challenges, it remains an accessible interface for the delivery of therapeutic carriers such as nanoemulsions both locally (topical and dermal) and systemically (transdermal). Nanoemulsions, once associated primarily with cosmetic applications, are now gaining prominence as essential components of skin cancer treatment strategies. This review explores the potential of topical nanoemulsions, shedding light on their ability to efficiently deliver a wide range of molecules, overcoming lipophilic barriers inherent to skin. In this comprehensive analysis of several distinct studies investigating NEs for skin cancer treatment, a diverse array of formulations and components were explored, revealing a spectrum of characteristics. The PDI spans from a minimum of 0.105 nm to a maximum of 0.421 nm, reflecting variations in droplet size distribution. Droplet sizes exhibit considerable diversity, ranging from a small 16 nm to a larger 200 nm, signifying varied potential for skin penetration. ZP values further contribute to this diversity, ranging from highly favorable (-66.6 mV) to less advantageous or near zero values, indicative of distinct surface charge characteristics. As healthcare costs continue to escalate, this nuanced overview of nanoemulsion characteristics provides valuable insights into their potential applications in the targeted treatment of melanoma and, to a lesser extent, non-melanoma skin cancers. The value of such innovative and safer drug delivery systems becomes increasingly evident. Here, we focus exclusively on the role of topical nanoemulsions in advancing skin cancer therapy.