So far the main focus in developing in vitro lipolysis models has been on simulating lipolysis in the upper intestinal tract, however, lately the importance of gastric lipolysis, catalysed by gastric lipase, has been realised and in vitro digestion models encompassing both gastric and intestinal lipolysis have been developed (Fernandez et al., 2009; Larsen et al., 2010). However, in this review we have chosen to focus on intestinal lipolysis, since this is the area where most work has been done. Different in vitro lipolysis models have been employed to characterize LSBDDS. Normally in vitro lipolysis is conducted in a medium containing bile acids and phospholipids in a thermostated vessel at a fixed stirring speed. During the lipolysis the hydrolysable ester bonds in the added LSBDDS are cleaved by a lipase source. Table 1 summarizes the experimental conditions for the three lipolysis models most extensively used for studying LSBDDS.