The purpose of this research was to formulate and systemically evaluate in vitro and in vivo performances of mucoadhesive
amoxicillin microparticles for the potential use in the treatment of gastric and
duodenal ulcers, which were associated with Helicobacter pylori. The
chitosan/
amoxicillin microparticles were successfully prepared in a process of
solution-enhanced dispersion by supercritical CO₂ (SEDS). The morphological characteristics of the mucoadhesive microparticles were studied under scanning electron microscope. The resulted microparticles with mean sizes ranged from 1.0 and 2.5 µm had good mucoadhesive properties. In vitro and in vivo mucoadhesive tests showed that
chitosan/
amoxicillin mucoadhesive microparticles adhered more strongly to gastric mucous layer and could retain in gastrointestinal tract for an extended period of time. The X-Ray
Powder Diffractometry and Differential Scanning Calorimetry analysis demonstrated that the SEDS process was a typical physical coating process to produce
drug-
polymer composite microparticles, which is favourable for drugs since there is no changes in chemistry. In vitro release test showed that
amoxicillin released faster in pH 1.0
hydrochloric acid (HCl) than in pH 7.8
phosphate buffer. In vivo H. pylori clearance tests were also carried out by administering
amoxicillin powder and mucoadhesive microparticles to H. pylori infectious Wistar rats under fed conditions at single dose or multiple dose(s) in
oral administration. The results showed that
amoxicillin mucoadhesive microparticles had a better clearance effect than
amoxicillin powder. In conclusion, the prolonged gastrointestinal residence time and enhanced
amoxicillin stability resulting from the mucoadhesive microparticles of
amoxicillin might make a contribution to H. pylori complete eradication.