Structural transformations also occurred upon mixing the lipidic particles with the polar lipids extracted from bacterial cell membranes. This is hypothesised to have a similar effect on drug release, and PEGylated surface stabiliser did not prevent this effect. While no evidence for lipid transfer was observed when exposed to live bacteria, it is thought that the cell fragments and debris constantly being produced as bacteria die may cause a similar effect. This effect might cause changes in lipid behaviour in applications where the lipidic formulations are exposed to large concentration of these fragments during residence time, for example in the case of suppository formulations.