Objective: This study aims to investigate the in vivo toxicological profile and
pre-clinical safety of surface modified self-nanoemulsifying formulations (SNEFs) for
oral delivery of a broad spectrum, anti-bacterial agent, gentamicin.
Method: SNEFs which were surface modified using PEG 4000, were formulated through
water titration method using appropriate mixtures of soybean oil, a combination of Kolliphor
® EL and Kolliphor® P188 as surfactants, and Transcutol® HP as co-surfactant, and
encapsulating gentamicin. SNEFs were characterized by measuring the droplet sizes, size
distribution and surface charges using a Zetasizer. The effects of the SNEFs on body
weight, haematological, biochemical, and histopathological factors of rats after oral administration
Results: Physicochemical characterization showed that the nanoformulations had droplet
sizes ranging from 96 - 121 nm with surface charges of -32 to -36 mV. SNEFs did not
show net suppression of body weights of rats. There were no clear indications of haematologic,
hepatic and renal injuries in the study rats due to flip-flops in the levels of haematologic,
hepatic and nephritic biomarkers evaluated. Histopathological organ examinations
corroborated findings from the effect of SNEFs on the liver and kidney but revealed
possible induction of astrocytosis in the cerebral cortex of rats.
Conclusion: Results of the study indicate that surface modified SNEFs of gentamicin
have a promising pre-clinical safety potential with minimum toxicity effects.