Lipid Nanoparticles for Oral Delivery of Poorly Water-Soluble Drug

The oral route remains the preferred method for drug administration; however, a significant proportion of new chemical entities exhibit poor aqueous solubility (BCS Class II and IV), leading to low and inconsistent bioavailability.This review aims to evaluate the current landscape of lipid nanoparticle (LNP) technologies, specifically Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs), as strategies to enhance the oral absorption of hydrophobic drugs. It synthesizes technical formulation parameters, absorption mechanisms, and translational barriers.The review examines formulation strategies, physicochemical characterization, and in vivo performance across various drug classes.lipid-based nanocarriers demonstrate 2- to 155-fold improvements in oral bioavailability by enhancing drug solubilization, protecting against gastrointestinal degradation, and facilitating intestinal lymphatic transport to bypass hepatic first-pass metabolism. Advanced NLC formulations offer superior drug loading and stability compared to first-generation SLNs. While LNPs present a robust platform for overcoming oral delivery barriers, challenges such as long-term storage stability, industrial scalability, and the need for more clinical validation remain. Future directions include the integration of 3D printing and hybrid lipid-polymer systems to further optimize delivery outcomes.