Drug encapsulation in pectin hydrogel beads- a systematic study of simulated digestion media

Pectin fragments have powerful anti-metastatic properties but the molecular structure of the active component(s) is still unknown. Pectin hydrogels are used to encapsulate drugs for oral drug delivery. This polysaccharide is not digested in the upper intestinal tract but its degradation in the colon releases oligomers with potential bioactivity. Here we tested the release of pectin fragments in standard simulated digestion media. Calcium-pectin beads, some of them further reticulated by polyethyleneimine and/or chitosan were incubated in simulated gastric, intestinal or colonic media in presence or absence of pancreatin or pectinases. Pectin oligomers were released only in simulated colonic media (i.e. in presence of pectinase) but the fragments were not longer than dimers which is much shorter than previously reported for pectin incubated with human faeces. The in vitro study of pectin digestion will therefore need simulated digestion media with much lower pectolytic enzyme concentrations.