Egg lecithin from different sources

Kansy et al. [547,550] used 10% wt/vol egg lecithin in dodecane. Cholesterol was added as well. We also chose to use 10% egg lecithin ( 60% grade ) in our laboratory. Tables 7.10 and 7.11 list the results of the various 10% egg lecithin models tested at plON. Some of the models were used in conjunction with a sink 

Without an artificial sink, the membrane retentions are very high, with many basic probe molecules showing R 80%. With the imposed sink, many of the retentions dropped by as much as 50%. Furthermore, just 0.5% wt/vol cholesterol in dodecane (in addition to the sink) caused increased retention to drop by at least a further 10-30%. It was not possible to form stable cholesterol-containing lipid models under sink conditions with Avanti s egg lecithin acceptor buffer solutions turned significantly turbid in the untenable model 13.1. 

The peculiar depression of metoprolol and quinine permeabilities in 2% DOPC (model 1.0) was not seen in the egg lecithin models. Metoprolol and quinine were significantly more permeable in the lecithins, in line with expectations based on relative octanol-water lipophilicities and relative in vivo absorptions of (3-blockers [593], 

Most of the permeabilities of the bases decrease steadily as the phospholipid fraction increases. There are some significant exceptions. Metoprolol, which is only moderately permeable in the DOPC lipid, becomes appreciably permeable in 10% soy lecithin. But at the 68% soy level, this molecule also shows reduced transport. 

The permeabilities of the acid examples rise with increasing phospholipid content, up to 20% lipid, with rank ordering preserved. Naproxen and ketoprofen 

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