Solid lipid nanoparticle-loaded mucoadhesive buccal films – Critical quality attributes and in vitro safety & efficacy

The objective of this work was to develop and characterize solid lipid nanoparticle (SLN)-loaded mucoadhesive films to reveal their potential as successful drug formulations. SLNs based on lipid (Lipoid S100) and surfactant (polysorbate 80) were prepared using the solvent-injection method, and their properties examined using experimental designs. Further, the marker coumarin 6 (C6) was solubilized in the particles as a model for a lipophilic drug. Lipid and surfactant concentrations influenced the particle size, while C6 had minor impact. The particle size distribution was narrow and the storage stability satisfactory for 4 months (4 ℃). The incorporation of the nanoparticles into a film matrix consisting of HPMC and glycerol, increased film thickness and flexibility, and slightly decreased the mechanical strength. The mucin interaction and disintegration time of the films were unimpaired. Film uniformity was satisfactory. Solubilisation in SLNs reduced the rate and extent of permeation of C6 through a monolayer of mucus-producing HT29-MTX cells. When the particles were incorporated into the mucoadhesive film, this effect was compensated for. In conclusion, this project was a first step in the successful development of an SLN-loaded mucoadhesive film formulation and served its purpose in revealing the formulation’s uniformity, mucoadhesiveness and biocompatibility