An Overview of Nanoemulgels for Bioavailability Enhancement in Inflammatory Conditions via Topical Delivery

The anti-inflammatory drugs that are generally available possess the disadvantage of hydrophobicity, which leads to poor permeability and erratic bioavailability. Nanoemulgels (NEGs) are novel drug delivery systems that aim to improve the solubility and permeability of drugs across the biological membrane. The nano-sized droplets in the nanoemulsion enhance the permeation of the formulation, along with surfactants and co-surfactants that act as permeation enhancers and can further improve permeability. The hydrogel component of NEG helps to increase the viscosity and spreadability of the formulation, making it ideal for topical application. Moreover, oils that have anti-inflammatory properties, such as eucalyptus oil, emu oil and clove oil, are used as oil phases in the preparation of the nanoemulsion, which shows a synergistic effect with active moiety and enhances its overall therapeutic profile. This leads to the creation of hydrophobic drugs that possess enhanced pharmacokinetic and pharmacodynamic properties, and simultaneously avoid systemic side effects in individuals with external inflammatory disorders. The nanoemulsion's effective spreadability, ease of application, non-invasive administration, and subsequent ability to achieve patient compliance make it more suitable for topical application in the combat of many inflammatory disorders, such as dermatitis, psoriasis, rheumatoid arthritis, osteoarthritis and so on. Although the large-scale practical application of NEG is limited due to problems regarding its scalability and thermodynamic instability, which arise from the use of high-energy approaches during the production of the nanoemulsion, these can be resolved by the advancement of an alternative nanoemulsification technique. Considering the potential advantages and long-term benefits of NEGs, the authors of this paper have compiled a review that elaborates the potential significance of utilizing nanoemulgels in a topical delivery system for anti-inflammatory drugs.