The influence of emulsifiers on drug diffusion from o/w creams

Histamine diffusion from various o/w creams containing different emulsifiers was studied. To confirm the diffusion study, possible drug-emulsifier interactions were studied by dialysis of their aqueous solutions. Interaction between histamine and anionic sodium laurylsulphate resulted in the absence of free diffusible histamine. No interaction was observed with the non-ionic cetomacrogol. Repulsion by the cationic cetrimide increased histamine diffusion rate and total diffusing amount because distribution occurred in accordance with the Donnan membrane equilibrium.