Abstract
Silymarin, a polyphenolic flavonolignan complex extracted from Silybum marianum (milk thistle), has long been recognized for its hepatoprotective, antioxidant, anti-inflammatory, and anticancer properties. Among its constituents, silybin is the most pharmacologically active and has been extensively studied in both preclinical and clinical settings. However, the clinical application of silymarin-based therapies remains limited by poor aqueous solubility, low oral bioavailability, rapid metabolism, and physicochemical instability. This review systematically outlines the pharmacokinetic challenges of silymarin and highlights recent advancements in formulation strategies designed to overcome these barriers. Key innovations include nanotechnology-enabled delivery systems, lipid-based carriers, water-soluble derivatives, bioavailability enhancers, parenteral and transdermal formulations, as well as controlled and synchronous release technologies. These approaches significantly improve tissue targeting, intracellular uptake, and pharmacological efficacy. Additionally, this review evaluates currently marketed silymarin formulations and recent clinical/preclinical evidence, revealing a persistent gap between laboratory advances and commercially available products. By synthesizing the mechanistic, regulatory, and manufacturability barriers that hinder translation, we delineate the key challenges that must be addressed to enable clinically deployable next-generation silymarin products. Collectively, these insights illustrate a paradigm shift in the modernization of phytomedicine, positioning silymarin as a model compound for the transformation of traditional herbal remedies into precision therapeutics through interdisciplinary drug delivery innovations.