Purpose: To optimize and characterize amoxicillin encapsulated in mucoadhesive alginate-coated
chitosan microparticles for the treatment of gastric and duodenal ulcers caused by
Helicobacter pylori
.
Methods: Eighteen batches of various ratios of chitosan, sodium alginate and calcium chloride were
prepared by ionotropic gelation method. The batches were optimized based on their particle size (PS)
and drug encapsulation efficiency (PDEE). Optimized batches were further evaluated for in vitro drug
release, bacterial susceptibility and mucoadhesion.
Results: Microparticle size ranged from 0.70 ± 0.37 to 5.25 ± 0.70 μm. Drug encapsulation efficiency
ranged from 95.79 to 97.42 % while maximum drug released after 24 h was 44.79 % in simulated
gastric fluid (SGF). Mucoadhesion reached a maximum of 76 % in simulated intestinal fluid (SIF). Drug
release followed Higuchi model of release kinetics while the release exponent, n, was > 0.9 in all the
formulations. There was a significant difference between the inhibition zone diameter (IZD) of the
optimized formulations and that of a commercial brand of amoxicillin when they were tested against
Salmonella typhi
and
Staphylococcus aureus
.
Conclusion: The mucoadhesive amoxicillin microparticles may improve the treatment of gastric ulcer
caused by H. pylori due to enhanced adhesion of the formulation to the pig’s ileum and the increased
antibacterial property against Salmonella typhi and Staphylococcus aureus.
