Gelatin coated hybrid lipid nanoparticles for oral delivery of amphotericin B.

Amphotericin B (AmB) loaded polymer lipid hybrid nanoparticles (AmB-PLNs) comprised of lecithin (anionic lipid) and gelatin (Type A, cationic below its isoelectric point 7.0-9.0) were prepared by a two-step desolvation method to improve the oral bioavailability of AmB. The optimized AmB-PLNs were found to have particle size 253 ± 8 nm, polydispersity index (PDI) 0.274 ± 0.008, and entrapment efficiency 50.61 ± 2.20% at 6% w/w of initial theoretical drug loading. Scanning electron microscopy (SEM) revealed spherical shaped nanoparticles whereas confocal laser scanning electron microscopy (CLSM) and fluorescent resonance energy transfer (FRET) analysis confirmed the orientation of the lecithin (located in the core) and gelatin (exterior coat) within the system. The developed formulation exhibited a sustained drug release profile with a release pattern best fitted to Higuchi kinetics. Experiments on Caco-2 cell lines revealed a 5.89-fold increase in the intestinal permeability of AmB-PLNs whereas in vivo pharmacokinetic studies exhibited a 4.69-fold increase in the oral bioavailability upon incorporation of AmB into PLNs as compared to that of free drug. The developed formulation showed significantly lesser hemolytic toxicity as compared to the free drug, Fungizone (micellar solution of AmB) and Fungisome (liposomal formulation of AmB). Furthermore, blood urea nitrogen (BUN) and plasma creatinine levels, indicative of nephrotoxicity, were also found to be significantly lesser for developed PLN formulation as compared to free drug and Fungizone while comparable to that of Fungisome. The histopathology of the kidney tissues further confirmed the absence of any changes in the morphology of the renal tubules.