title: Evaluation of cytotoxicity of surfactants used in self-micro emulsifying drug delivery systems and their effects on paracellular transport in Caco-2 cell monolayer.
abstract: The objective of this study was to examine the cellular effects of the members of two non-ionic amphiphilic tenside groups and their mixtures on human Caco-2 cell monolayers as dependent upon their chemical structures and physicochemical properties. The first group of polyethylene glycol esters is represented by Polysorbates and Labrasol alone and in blends, while the members of the second group. Capryol 90, Capryol PGMC, Lauroglycol 90 and Lauroglycol FCC were used as propylene glycol esters. They are increasingly used in SMEDDS as recent tensides or co-tensides to increase hydrophobic bioavailability of a drug. Critical micelle concentration was measured by determination of surface tension. CMC refers to the ability of solubilization of surfactants. Cytotoxicity tests were performed on Caco-2 cell monolayers by MTT and LDH methods. Paracellular permeability as a marker of the integrity of cell monolayers, was examined with Lucifer yellow assays combined with TransEpithelial Electrical Resistance (TEER) measurements. The effect of these surfactants on tight junctions as evidence for paracellular pathway was also characterized. The results of cytotoxicity assays were in agreement, and showed significant differences among the cytotoxic properties of surfactants in a concentration-dependent manner. Polysorbates 20, 60, 80 are the most toxic compounds. In the case of Labrasol, the degree of esterification and lack of sorbit component decreased cytotoxicity. If the hydrophyl head was changed from polyethylene glycol to propylene glycol the main determined factor of cytotoxicity was the monoester content and the length of carbon chain. In our CMC experiments, we found that only Labrasol showed expressed cytotoxicity above the CMC. It refers to good ability of micelle solubilization of Labrasol. In our paracellular transport experiments each of polyethylene glycol surfactants (Polysorbates and Labrasol) altered TEER values, but propylene glycol esters did not modify the monolayer integrity. Polyethylene glycol esters alone and in blends (0.05% Labrasol--0.001% Polysorbates 20, 60, 80) were able to increase Lucifer yellow permeability significantly below the IC₅₀ concentration. On the other hand Labrasol and Polysorbates 20 have expressed effect on tight junctions of Caco-2 monolayer. It could be concluded that polyethylene glycol ester-type tensides were able to enhance the paracellular permeability by the redistribution of junctional proteins. Our results might ensure useful data for selection of suitable tensides, co-tensides and tenside mixtures for SMEDDS formulations.
authors: Department of Pharmaceutical Technology, Faculty of Pharmacy, Medical and Health Science Center, University of Debrecen, Hungary.
authors: Zoltán
authors: Z
authors: Ujhelyi
authors: Ferenc
authors: F
authors: Fenyvesi
authors: Judit
authors: J
authors: Váradi
authors: Pálma
authors: P
authors: Fehér
authors: Tímea
authors: T
authors: Kiss
authors: Szilvia
authors: S
authors: Veszelka
authors: Mária
authors: M
authors: Deli
authors: Miklós
authors: M
authors: Vecsernyés
authors: Ildikó
authors: I
authors: Bácskay
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D018938:Caco-2 Cells; D002463:Cell Membrane Permeability / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D016503:Drug Delivery Systems; D006801:Humans; D007408:Intestinal Absorption; D011092:Polyethylene Glycols / Q000737:chemistry; D011409:Propylene Glycols / Q000737:chemistry; D013501:Surface-Active Agents / Q000494:pharmacology*
chemical_list: D011409:Propylene Glycols; D013501:Surface-Active Agents; D011092:Polyethylene Glycols