The Relationship between Transport-enhancement Effects and cell viability by capric acid sodium salt, monocaprin, and dicaproin

Using Caco-2 cell monolayers and MTT assay, the relationship between cell viability (a) and transport-enhancement effect of 1,2-dicaproin (C6DG), monocaprin (C10MG), and capric acid sodium salt (C10FANa) was examined. Transport enhancement effect was assessed by apparent permeability (P_app) of penicillin V. There was a linear relationship between (P_app-aS_a) and (1-a) values, where S_a was the apparent permeability for the viable cells. The apparent permeability for the damaged cells (S_d) was evaluated from the slope of the line. Each of the enhancer compounds gave a different S_d value 2.00×10^-4, 0.82×10^-4, and 0.10×10^-4 cm/s for C6DG, C10MG, and C10FANa, respectively, but the value was independent of its concentration for C10MG and C10FANa. C6DG would be the safest enhancer among the three compounds because of its high S_d value at the low level of cell damage. S_d could be used as a criterion for estimating the safety of enhancers.