DOPC with Negative Lipids without Sink

5 DOPC with Negative Lipids without Sink 

The two-component lipid models were also characterized in the absence of sink conditions (Table 7.8). Comparisons between models 7.0 (Table 7.7) and 1.0 (Table 7.5) suggest that negative charge in the absence of sink causes the permeabilities of many of the bases to decrease. Exceptions are quinine, prazosin, primaquine, ranitidine, and especially metoprolol. The inclusion of 0.6% PA causes Pe of metoprolol to increase nearly 10-fold, to a value twice that of propranolol, a more lipophilic molecule than metoprolol (based on the octanol-water scale). Naproxen and ketoprofen become notably more permeable in the two-component system. Surprisingly, the neutral progesterone becomes significantly less permeable in this system. 

With the noted exceptions above, the other negative-lipid combinations (Table 7.8) show consistently lower permeabilities compared to neutral DOPC. Surprisingly, the retentions are not concomitantly higher than in the neutral DOPC lipid. 

---