A Comprehensive Review on Solid Lipid Nanoparticles as a Carrier for Oral Absorption of Phyto-Bioactives

Phyto-bioactive (PB) compounds are naturally occurring substances derived from plants that offer significant health benefits ranging from antioxidant and anti-inflammatory activities to potential cancer-fighting properties. However, their widespread application is limited by several inherent limitations, such as low bioavailability, poor biostability, limited aqueous solubility, and no site-specific target. Additionally, the necessity for high concentrations of effective PBs doses further restricts their use. Encapsulating PBs in suitable nanocarriers, particularly solid lipid nanoparticles (SLNs), can enhance their stability in biological environments, improve water solubility, enable controlled release, and allow for targeted delivery. This innovative approach increases bioavailability, reduces toxicity, and potentially lowers effective dosages. The current review examines the critical factors influencing oral PBs delivery, explores how biocompatible and biodegradable SLNs can be optimized to overcome these challenges, and discusses emerging techniques in nanoparticle design that could further enhance the efficacy of PBs delivery systems.