ABSTRACT
The gastrointestinal environment may well be the most hostile environment liposomes could possibly encounter, exposing them to extreme pH conditions, high concentrations of detergent (bile salts), and high concentrations of enzymes in the gut lumen and intestinal cell walls. Yet phospholipid compositions have been found that can withstand such insults with remarkable stability. For instance, a formulation that has been shown repeatedly to be stable when exposed to pancreas lipase solution or physiologic bile salt solution is distearoylphosphatidylcholine/cholesterol in a 7:2 molar ratio (415,416).
