SOLID LIPID NANOPARTICLES IN LYMPH AND PLASMA AFTER DUODENAL ADMINISTRATION TO RATS

Purpose. To evaluate the uptake and transport of solid lipid nanoparti cles (SLN), which have been proposed as alternative drug carriers, int o the lymph and blood after duodenal administration in rats. Methods. Single doses of two different concentrations of aqueous dispersions of unlabelled and labelled SLN (average diameter 80 nm) were administere d intraduodenally to rats. At different times, samples of lymph were w ithdrawn by cannulating the thoracic duct and blood was sampled from t he jugular vein. Monitoring continued for 45 and 180 minutes, for unla belled and labelled SLN respectively. The biological samples were anal ysed by photon correlation spectroscopy (PCS), transmission electron m icroscopy (TEM) and gamma-counting. Results. TEM analysis evidenced SL N in lymph and blood after duodenal administration to rats; the size o f SLN in lymph did not change markedly compared to that before adminis tration. The labelled SLN confirmed the presence of SLN in lymph and b lood. Conclusions. The uptake and transport of SLN in the lymph, and t o a lesser extent in the blood, were evidenced. The in vivo physical s tability of SLN may have important implications in designing drug-carr ying SLN.