In vitro–in vivo evaluation of chitosan-PLGA nanoparticles for potentiated gastric retention and anti-ulcer activity of diosmin

Abstract

Background

Diosmin showed poor water solubility and low bioavailability. Poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles were successfully used to improve the drugs solubility and bioavailability. Coating of PLGA nanoparticles with chitosan can ameliorate their gastric retention and cellular uptake.

Methodology

PLGA nanoparticles of diosmin were prepared using different drug and polymer amounts. Nanoparticles were selected based on entrapment efficiency% (EE%) and particle size measurements to be coated with chitosan. The selected nanoparticles either uncoated or coated were evaluated regarding morphology, ζ-potential, solid-state characterization, in vitro release, storage stability, and mucoadhesion. The anti-ulcer activity (AA) against ethanol-induced ulcer in rats was assessed through macroscopical evaluation, histopathological examination, immunohistochemical localization of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and transmission electron microscopic examination of gastric tissues compared to free diosmin (100 mg/kg) and positive control.

Results

Based on EE% and particle size measurements, the selected nanoparticles, either uncoated or coated with 0.1% w/v chitosan, were based on 1:15 drug-PLGA weight ratio and 20 mg diosmin employing methylene chloride as an organic phase. Examination by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed nanoscopic spherical particles. Drug encapsulation within the selected nanoparticles was suggested by Fourier transform-infrared, differential scanning calorimetry (DSC) and X-ray diffractometry results. Chitosan-coated nanoparticles were more stable against size enlargement probably due to the higher ζ-potential. Only coated nanoparticles showed gastric retention as revealed by SEM examination of stomach and duodenum. The superior AA of coated nanoparticles was confirmed by significant reduction in average mucosal damage, the majority of histopathological changes and NF-κB expression in gastric tissue when compared to positive control, diosmin and uncoated nanoparticles as well as insignificant difference relative to normal control. Coated nanoparticles preserved the normal ultrastructure of the gastric mucosa as revealed by TEM examination.

Conclusion

The optimized chitosan-coated PLGA nanoparticles can be represented as a potential oral drug delivery system of diosmin.

Keywords:

• diosmin
• poly(d,l-lactide-co-glycolide)
• chitosan-coating
• polymeric nanoparticles
• gastric retention
• anti-ulcer activity

Acknowledgment

The authors would like to thank Dr Walaa Awadin, Associate Professor, Department of Pathology, Faculty of Veterinary Medicine, Mansoura University, for her technical support and specimens examination during macroscopical and histopathological evaluation as well as immunohistochemical localization of NF-κB. The authors would also like to thank Dr Abd El-Fattah BM El-Beltagy, Associate Professor, Department of Zoology, Faculty of Science, Damanhour University, for examination of the ultrastructure of the gastric mucosa by TEM. The authors are grateful for Purac Biomaterials, Holland for kindly supplying the poly(lactic-co-glycolic acid (PLGA).

Disclosure

The authors report no conflicts of interest in this work.