Lipid nanoparticles (LNPs) have emerged as a leading nonviral delivery system for ribonucleic acid (RNA)-based therapeutics, offering a scalable and efficient platform for both prophylactic and therapeutic applications. Compared to traditional excipients and delivery methods, LNPs provide several distinct advantages that make them particularly well-suited for nucleic acid delivery. These include enhanced cellular uptake, potential for reduced systemic toxicity, organ-specific biodistribution and protection of RNA cargo from enzymatic degradation. LNPs also facilitate endosomal escape, a critical barrier in the intracellular delivery of RNA molecules, thereby improving the overall transfection efficiency and therapeutic index. Their tunable composition allows for precise control over pharmacokinetics, immunogenicity and tissue targeting, which are critical in the development of vaccines, gene therapies, other RNA-based interventions and precision medicines. In addition, LNP-based nonviral delivery methods may offer several advantages over viral vectors, including cost-effectiveness, scalable and rapid manufacturing and greater adaptability for developing personalized gene therapy products. These features align well with platform technology designations and support a bespoke, umbrella trial approach. This review provides a comprehensive overview of the critical components and design considerations of LNP-based delivery systems, with a focus on messenger RNA, guide RNA payloads and lipid components. We discuss the differences between prophylactic and therapeutic formulations, key quality and purity attributes required for safe and effective use. Particular attention is given to the complexities of LNP formulation, including the characterization, production and quality control of both RNA cargo and lipid components. We also highlight current regulatory challenges, including the lack of standardized testing methods, unclear excipient classification and the absence of compendial monographs for the ionizable and pegylated lipid components. Essential questions for optimizing LNP formulations are discussed along with the evolving regulatory landscape and current clinical applications. As the field evolves to incorporate novel RNA modalities such as short-interference RNA, RNAi, self-replicating RNA and circular RNAs, the need for robust quality standards and regulatory clarity becomes more vital. This review underscores the urgent need for collaboration between industry and regulatory to establish harmonized framework for LNP development to ensure safety, efficacy and rapid translation of RNA-LNP therapeutics across diverse disease areas.
