Drug Release, Entrapment Efficacy, and Drug Loading Capacity of Taxanes Loaded Solid Lipid Nanoparticles (SLNs)

Background: Solid lipid nanoparticles (SLNs) are submicron carriers with great promise in revolutionizing cancer therapy. They offer a potential solution to the side effects of conventional anticancer drugs, such as systemic toxicity and non-specific distribution. Taxanes, a widely used class of anticancer agents, have been increasingly incorporated into nano-lipid formulations (NLFs) to enhance their therapeutic index. Objective: Designing optimal SLN formulations with enhanced drug loading capacity (DLC%), entrapment efficiency (EE%), and controlled drug release profiles is a significant challenge in pharmaceutical nanotechnology. This review, the first of its kind, systematically explores the key factors influencing EE%, DLC%, and the release behavior of Taxane-loaded SLNs. It provides a comprehensive and updated perspective, equipping you with the latest knowledge in this field. Methods: This narrative review adopts a comprehensive approach to examine the formulation variables that affect EE%, including lipid type, drug properties, surfactants, co-surfactants, emulsifiers, and conjugates. It also outlines the critical parameters that influence drug release, such as particle size, co-loaded drugs, types of lipids and emulsifiers, surface modifiers, release media, and environmental conditions, including pH. The review process involved thoroughly analyzing existing literature and studies in pharmaceutical nanotechnology. Results: Numerous studies demonstrate that EE% is significantly affected by the physicochemical properties of both the drug and lipid matrix and the choice and concentration of surfactants (e.g., Poloxamer, Tween-80, Solutol HS-15, lecithin). Certain modifications, such as conjugation with Hyaluronic acid, Chitosan derivatives, and PEGylation, tend to lower EE% but improve targeted release. Incorporation of compounds like α-lipoic acid, Ketoconazole, or co-loaded PTX and DTX results in a slower drug release profile. Conversely, siRNA incorporation often accelerates drug release. The release rate is also modulated by environmental pH and the nature of the lipid carriers. Ideal SLN formulations demonstrate high EE% and DLC% along with sustained and controlled release of Taxanes. Conclusion: Multiple formulation and environmental factors influence EE%, DLC%, and the drug release behavior of Taxane-loaded SLNs. Understanding these variables is not just important, but it is the key to rationalizing effective and stable nano-lipid formulations in cancer therapy. It is a fascinating and crucial area of study that demands our attention.