IN-VITRO SKIN IRRITATION TESTING OF PETROLEUM-BASED COMPOUNDS IN RECONSTITUTED HUMAN SKIN MODELS

Seven petroleum-based test materials were evaluated for skin irritation potential using full-thickness reconstituted human skin models (skin(2) Model ZK1300 from Advanced Tissue Sciences, Inc., and Living Skin Equivalent (LSE) from Organogenesis, Inc.). Test materials were dosed undiluted in triplicate onto the epidermal side of the tissues that were incubated in polyethylene bags designed to minimize cross-contamination and loss of volatile constituents. The endpoints measured were thiazolyl blue (MTT) reduction and lactate dehydrogenase (LDH), prostaglandin E(2) (PGE(2)), and interleukin-l alpha (IL-1 alpha) release into spent media from treated and untreated tissues. Data from these tests were correlated with Draize primary dermal irritation index (PDII) scores using Cooper's criteria. Results showed that all endpoints measured approximated the skin irritationpotential of the test materials, with the exception of IL-1 alpha in the skin(2) Model ZK1300, in which significant levels of IL-1 alpha could not be detected. Further refinement and validation of this methodology may provide industrial scientists with a practical method for evaluating volatile test materials in commercially available tissue culture.