Advancements in polymer- and lipid-based nanoparticles for enhancing drug solubility, stability, and bioavailability: an integrative and forward-looking review

Limited oral bioavailability, poor water solubility, and chemical instability continue to be significant obstacles in the development of pharmaceutical treatments. These issues have encouraged researchers to look forward to nanoscale, especially polymer and lipid-based materials, as practical and adaptable solutions. Precise polymer- and lipid-based nanoparticles (NPs) have become two of the most adaptable and clinically relevant technologies that may overcome these constraints because of their physicochemical properties. This review’s primary goal is to incorporate recent developments in both polymeric and lipid nanoparticle (LNP) systems, which emphasize the different but complementary strategies for improving the solubility and stability of various therapeutic compounds. The discussion covers developments in solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), liposomes, and lipid nanoparticles, along with advancements in polymeric nanocarriers such as dendrimers, poly(lactic-co-glycolic acid) (PLGA) nanoparticles, polymeric micelles, and hybrid polymer systems. This study will offer newer directions in the field, including stimuli-responsive nanocarriers, hybrid lipid–polymer architectures, scalable green production, and precise surface engineering for targeted distribution, in addition to outlining established processes. Particular attention is given to how formulation choices influence pharmacokinetic behavior, which is an area that is often mentioned but not deeply integrated in many existing reviews. The article additionally addresses ongoing challenges such as maintaining long-term stability, preventing premature drug leakage, minimizing toxicity, and navigating regulatory barriers. In order to encourage future innovation in nanoparticle-enabled drug delivery, this article attempts to provide a broad yet distinctively structured viewpoint to the Research Topic by combining multidisciplinary discoveries from materials science, pharmaceutics, and nanomedicine.