In vitro skin decontamination model: comparison of salicylic acid and aminophylline.

Objective: This study compared three model decontaminant solutions (distilled water, 10% distilled water and soap and methanol) for their ability to remove salicylic acid and aminophylline from an in vitro skin model.

Materials And Methods: Human abdominal skin was dosed with 20 µL of either [(14)C]-aminophylline or [(14)C]-salicylic acid on 1 cm(2) per skin. After each exposure time (5, 30 and 60 min post-dosing, respectively), surface skin was washed three times with each solution and tape stripped 10 times. Wash solutions, tape strips, receptor fluid and remaining skin were then analyzed with liquid scintillation counting to quantify the amount of salicylic acid and aminophylline.

Results: Total mass balance recovery for each chemical at three time exposure points was between 73.6 and 101.5%, except at 60 min where aminophylline was only 42.5%. Majority of salicylic acid and aminophylline were recovered from washing solution when compared to stratum corneum, epidermis, dermis, surrounding skin and receptor fluid.

Conclusion: The three tested decontaminates possessed similar effectiveness in removing lipophilic and hydrophilic chemicals from the skin. Due to diminishing decontamination efficacy with time, it is suggested that skin should be washed as soon as possible following contamination to minimize percutaneous penetration and the deleterious effects associated with skin reservoir content.