Transport of alkamides from Echinacea species through Caco-2 monolayers
ABSTRACT To gain more insights into the human intestinal absorption of alkamides from Echinacea species, transport studies were performed with the human adenocarcinoma colonic cell line Caco-2 (ATCC) as a model to assess the epithelial transport of dodeca-2 E,4 E,8 Z,10 E/ Z-tetraenoic acid isobutylamides (1/ 2). 30 minutes after apical loading of 25 microg/ml 1/ 2, about 15 % of these alkamides were detectable on the basolateral side. Close monitoring of the transport during 6 hours revealed a nearly complete transport to the basolateral side after 4 hours and no significant metabolism was observable. Transport experiments performed at 4 degrees C showed only a slight decrease in transport, which is a strong hint that dodeca-2 E,4 E,8 Z,10 E/ Z-tetraenoic acid isobutylamides (1/ 2) cross biological membranes by passive diffusion. Nearly the same results were obtained after preincubation of the Caco-2 cells with lipopolysaccharides (LPS) or phorbol 12-myristate-13-acetate (PMA) to mimic an inflammatory status. These results support the assumption that the alkamides can be easily transported from the intestinum and hence may contribute to the in vivo effects of Echinacea preparations.
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ABSTRACT: A poorly water soluble acidic active pharmaceutical ingredient (API) was transformed into an ionic liquid (IL) aiming at faster and higher oral availability in comparison to a prodrug. API preparations were characterized in solid state by single crystal and powder diffraction, NMR, DSC, IR and in solution by NMR and ESI-MS. Dissolution and precipitation kinetics were detailed as was the role of the counterion on API supersaturation. Transepithelial API transport through Caco-2 monolayers and counterion cytotoxicity were assessed. The mechanism leading to a 700 fold faster dissolution rate and longer duration of API supersaturation of the ionic liquid in comparison to the free acid was deciphered. Transepithelial transport was about three times higher for the IL in comparison to the prodrug when substances were applied as suspensions with the higher solubility of the IL outpacing the higher permeability of the prodrug. The counterion was nontoxic with IC50 values in the upper μM / lower mM range in cell lines of hepatic and renal origin as well as in macrophages. The IL approach was instrumental for tuning physico-chemical API properties, while avoiding the inherent need for structural changes as required for prodrugs.Pharmaceutical Research 12/2014; 32(6). DOI:10.1007/s11095-014-1607-9 · 3.95 Impact Factor
Journal of Surgical Research 02/2011; 165(2):222-222. DOI:10.1016/j.jss.2010.11.549 · 2.12 Impact Factor