Objective: The aim of this study was to evaluate how the membrane transport of diclofenac on presence of different types of food is modified.
Methods: The interaction of diclofenac, as a pure substance and solid dispersions of the active ingredient, with different types of foods was investigated in vitro condition using a modified Franz diffusion cell.
Results: The amount of diclofenac transported through a lipophilic membrane was reduced by the presence of foodstuffs in artificial gastric juice and intestinal juice also, both in the case of the pure substance and solid dispersions also. The only exception was the case of milk in artificial gastric juice, when the amount of diclofenac in the receiving compartment increased about 2-fold compared to the fasted conditions simulating media. In the case of the solid dispersions of diclofenac the membrane transport increased in all cases compared to the pure substance, but was also reduced by the foods.
Conclusions: It was concluded that, the presence of different foodstuffs can influence the membrane transport of diclofenac – by inhibiting its solubility – and these differences observed in vitro can lead to modifications in the in vivo pharmacokinetic parameters. The lowest difference in diclofenac membrane transport was observed in the case of diclofenac:PEG 6000 solid dispersion prepared in 1:5 mass ratio.