Elimination study of intact lipid nanocapsules after intravenous rat administration

Abstract

Aim: The present study investigated renal elimination after intravenous administration of four different formulations of lipid nanocapsules (LNCs) containing dyes adapted to Förster resonance energy transfer (FRET-LNCs).Materials & methods: FRET-LNCs of 85 or 50 nm with or without a pegylated surface were injected and collected in the blood or urine of rats at different time points. Quantitative analysis was performed to measure intact FRET-LNCs.Results & conclusion: No intact LNCs were found in urine (0 particles/ml) for all formulations. The 50-nm pegylated LNCs were eliminated faster from the blood, whereas 85-nm pegylated LNCS were eliminated slower than nonpegylated LNCs. Elimination of FRET-LNCs was mainly due to liver tissue interaction and not renal elimination.

Keywords: FRET; drug delivery; lipid nanocapsules; pharmacokinetics; renal elimination.

Figure 1.

Stability of fluorescence resonance and energy transfer lipid nanocapsules (FRET-LNCs) in rat urine over 24 h. This diagram represents the percentage normalized particle concentration (%C_N) in urine and PBS for each FRET-LNCs subtype. The experiment was conducted in triplicate and reported as the arithmetic mean and standard deviation (whisker plot). LNC: Lipidic nanocapsule; PBS: Phosphate buffered saline; Urine: Rat urine.

Figure 2.

Plasma particle concentration versus time profile of 50- and 85-nm fluorescence resonance and energy transfer lipid nanocapsules following intravenous bolus. Data are reported as the arithmetic mean and standard deviation (whisker plot). LNC Lipidic nanocapsule.