THE EFFECT OF RECEPTOR PHASE-COMPOSITION ON THE PERMEABILITY OF HAIRLESS MOUSE SKIN IN DIFFUSION CELL EXPERIMENTS

The effect of different antimicrobial agents (0.1% and 0.04% formaldehyde and 0.002% NaN3) in the receptor phase of diffusion cells and the influence of the length of time of exposure of hairless mouse skins in the diffusion cells to the receptor phases have been evaluated by determining their effect on the flux of theophylline in diffusion cell experiments. If the length of exposure to the receptor phase was 4 h before application of theophylline, the flux of theophylline was essentially the same regardless of the antimicrobial agent used. If 0.1% formaldehyde was the agent used, the flux of theophylline remained relatively constant regardless of the time of exposure to the receptor phase. For the other two agents (0.04% formaldehyde and 0.002% NaN3) the flux of theophylline increased sharply with increased time of exposure. This result is apparently due to microorganism growth in the receptor phases containing 0.04% formaldehyde and 0.002% NaN3.