Evaluation of the digestibility of solid lipid nanoparticles of glyceryl dibehenate produced by two techniques: Ultrasonication and spray-flash evaporation

Objective: To evaluate the digestibility of Solid Lipid Nanoparticles (SLN) of glyceryl dibehenate prepared either with surfactants by ultrasonication or without surfactant by spray-flash evaporation. Methods: SLN of glyceryl dibehenate (Compritol (R) 888 ATO) were produced by two processes: (i) high-shear homogenization with a solution of water-soluble surfactants followed by ultrasonication (ii) and Spray-Flash Evaporation (SFE) of the pure lipid. The digestibility of these nanoparticles was then tested by in vitro lipolysis using a pH-stat apparatus and the assay of glycerides by gel phase chromatography. Results: SLN of glyceryl dibehenate prepared by ultrasonication exhibited a mean particle size of 180 nm and showed a limited digestion of the lipid excipient. SLN comprising only glyceryl dibehenate produced by SFE have a mean particle size between 235 and 411 nm depending on process parameters. These nanoparticles were not digested by lipases. The presence of surfactant at the lipid/water interface of the SLN seems to be mandatory to allow the adsorption of the lipase and degradation of glyceryl behenate. Conclusions: Glyceryl dibehenate as a solid particle - even as a SLN - is not digested by pancreatin during in vitro lipolysis test.