In-vitro evaluation of solid lipid nanoparticles: ability to encapsulate, release and ensure effective protection of peptides in the gastrointestinal tract

The objective of this study was to encapsulate a model water-soluble peptide in biodegradable and biocompatible solid lipid-based nanoparticles, i.e. Solid Lipid Nanoparticles (SLN) and Nanostructured Lipid Carriers (NLC) in order to protect it from metabolic degradation. Leuprolide (LEU) and a LEU-docusate Hydrophobic Ion Pair (HIP) were encapsulated in SLN and NLC by High Pressure Homogenization. The particles were characterized regarding their Encapsulation Efficiency (EE), size, morphology, peptide release in FaSSIF-V2, and protective effect towards proteases. Nanoparticles of 120 nm with platelet structures were obtained. Formation of HIP led to a significant increase in LEU EE. Particle size was moderately affected by the presence of simulated fluids. Nonetheless, an important burst release was observed upon dispersion in FaSSIF-V2. NLC were able to improve LEU-HIP resistance to enzymatic degradation induced by trypsin but presented no advantages in presence of α-chymotrypsin. SLN provided no protection regarding both proteases. Despite an increased amount of encapsulated peptide in solid lipid-based nanoparticles following HIP formation, the important specific surface area linked to their platelet structures resulted in an important peptide release upon dispersion in FaSSIF-V2 and limited protection towards enzymatic degradation.Graphical abstract
Source: International Journal of Pharmaceutics - Category: Drugs & Pharmacology Source Type: research