Application of Nanostructured Lipid Carriers (NLCs) for the Delivery of Antiviral Agents in Herpes Infections: A Comprehensive Review

Herpes simplex virus (HSV) infections remain a major global health burden due to their high prevalence, lifelong latency, frequent recurrence, and increasing resistance to conventional antiviral therapies. Currently available antiviral agents such as acyclovir, valacyclovir, famciclovir, and penciclovir suffer from limitations including poor bioavailability, short half-life, limited skin and mucosal penetration, frequent dosing, and systemic side effects. Nanostructured lipid carriers (NLCs), a second-generation lipid-based nanocarrier system, have emerged as a promising strategy to overcome these challenges. NLCs combine solid and liquid lipids to create an imperfect crystal lattice, resulting in improved drug loading, stability, controlled release, and enhanced penetration across biological barriers. This review provides a comprehensive overview of herpes virus infections, current antiviral therapies, and their limitations, followed by an in-depth discussion of NLCs, including their composition, preparation methods, characterization, and advantages. The application of NLCs for the delivery of antiviral agents in herpes infections is critically analyzed, with emphasis on topical, oral, and mucosal delivery routes. Preclinical and clinical evidence supporting the efficacy of NLC-based antiviral delivery systems is discussed, along with challenges, safety considerations, and future perspectives. Overall, NLCs represent a versatile and promising nanotechnology platform for improving the therapeutic outcomes of antiviral therapy in herpes infections.