Percutaneous absorption of 4 organic solvents in the guinea pig (II). Effect of surfactants.

Percutaneous absorption of 4 organic solvents (1,1,1-trichloroethane, 1,1,2-trichloroethane, toluene and butanol) from various colloidal preparations in a surfactant-water-organic solvent system was studied in vivo in guinea pigs. The preparations examined were binary solutions of organic solvents and surfactants, o/w emulsions and microemulsions. Phase diagram, birefringence microscopy and droplet size distribution analysis were used for characterization of the preparations. It was found that skin absorption of the solvents depends on the type of surfactant, type of preparation and also on phase equilibria in the systems studied. The presence of nonionic surfactants in the solvents and in a microemulsion with butanol caused skin absorption to decrease. A reduced uptake of solvents from o/w emulsions was observed. The absorption of butanol from a microemulsion with anionic surfactant was greater than from the pure solvent.