5 ( Fig. 3a), indicating that the level of lipids present in FaSSGF was too low to significantly solubilize the studied compounds. All compounds present in their neutral form at pH 2.5 had higher solubility in NaClpH2.5,20%Ethanol compared to that in blank medium
( Fig. 3b). The weak basic compounds were completely charged at pH 2.5 and were unaffected by lipid aggregates, ethanol content or combination thereof. The Sapp of felodipine and tolfenamic acid was over 20 times higher in medium with lecithin, taurocholate and ethanol than without ( Fig. 3c). The http://www.selleckchem.com/products/sch772984.html remaining non-ionizable compounds and weak acids showed 7–10-fold higher solubility in the ethanol-spiked FaSSGF compared to the NaCl solution. Similar trends were observed when FaSSGF with and without ethanol were compared. Here the weak bases were equally soluble in both media, whereas neutral compounds were up to 15-fold more soluble in ethanol containing FaSSGF ( Fig. 4). Two of the model compounds with basic functions, cinnarizine and terfenadine, were unaffected
by the simulated ethanol intake (Fig. 5). However, the absorption of dipyridamole was increased considerably with a relative AUC increase greater than 40% and with a similar increase in peak plasma concentration (Table 4). The plasma peak concentration time (Tmax) decreased almost 4.5 h. Indomethacin and indoprofen doses were according to the simulations readily absorbed HA-1077 solubility dmso in both the fasted state and with concomitant ethanol intake while approximately 80% of administered tolfenamic acid was absorbed. The predicted AUC of these acidic compounds was hence unaffected by concomitant ethanol unless intake. Indomethacin and indoprofen Cmax increased slightly while the Cmax of tolfenamic acid remained unchanged. For non-ionizable compounds the AUC increased between 15% (griseofulvin) and 105% (felodipine) when ethanol was present in the gastric and duodenal simulation compartments. The fraction absorbed of felodipine doubled; Cmax increased almost 150% and Tmax decreased by 1 h after simulated intake of alcohol. Progesterone AUC and Cmax increased with 17% and
16%, respectively, and Tmax decreased by 30 min as a result of the ethanol effect on Sapp. The simulations with smaller particles (5 μm in diameter) led to a higher fraction of the dose absorbed and/or an overall more rapid absorption for all compounds. The changes in the plasma-concentration curves observed with ethanol were not as pronounced for the small particle size compared to the larger one (25 μm in diameter). Further, the simulations in which ethanol was excluded in the duodenal compartment showed substance-specific results. No effect on the absorption of dipyridamole, griseofulvin and progesterone was observed when ethanol only was present in the gastric compartment and hence, influenced the concentration reached in the stomach but not in the duodenum.