Herbal drugs-loaded soft nanoparticles for treating skin disorders: Where do we stand?

Skin conditions can greatly affect the overall well-being of individuals. They are often accompanied by various side effects and the pharmacological treatment often has low efficacy. This represents a major global health issue. Plant extracts are a popular alternative due to their multiple biological properties, including antioxidant, anti-inflammatory, and antimicrobial actions, which show potential for managing skin injuries. However, plant-derived extracts have limitations such as low solubility and tissue permeability, and chemical instability. Therefore, researchers are exploring herbal drugs for cutaneous application using nano-based formulations as a promising strategy. This scoping review aims to determine the current status of using soft nanoparticles incorporating plant extracts for topical therapy of skin diseases. The review covers general aspects of plant species and pharmacogen used in the extract, the extracting solvent, nanostructure, topic formulation, in vitro and in vivo methods, and the therapeutic purpose. Various nanosystems have been studied as delivery platforms for plant-derived substances intended for cutaneous administration, showing improved skin permeability, the photostability of phytochemicals, and enhanced biological outcomes assessed by in vitro and in vivo approaches. Despite progress made, there remain unresolved issues related to plant sourcing, phytochemical profiles, formulation stability, cutaneous administration, and toxicity. Standardizing plant conditions, studying the complete matrix of herbal drugs, characterizing stable formulations, assessing toxicity through diverse methods, and conducting clinical studies are needed to address these issues.