In addition to the assays described in other sections, IIVS also offers the following testing services as part of its standard catalogue:
The rates of absorption and passage of test chemicals into and through human skin can be modeled in the in vitro percutaneous penetration assay. By utilizing various skin models and test protocols, a variety of dermal absorption and percutaneous penetration endpoints may be determined, such as the absorption and passage through the lipophilic stratum corneum, absorption and passage through the epidermis and dermis, and the potential for metabolism within the viable epidermis. Skin penetration assays may be utilized to evaluate the rate of absorption or passage of individual chemicals or formulation components in personal and skin care products, pesticides and herbicides, and pharmaceuticals to enhance product development goals, or to address product safety issues. Skin penetration assays may also be used to determine the extent of absorption of potentially toxic materials, for example, to address EPA and worker safety issues.
Phototoxicity Assay Using the Epiderm Skin Model
Combining the EpiDerm three-dimensional skin model into the phototoxicity protocol allows one to test solid or non-water soluble materials. Direct application of the test material can be made to the surface of the tissue which can then be irradiated and compared to non-irradiated treated tissue to determine the test material’s phototoxic potential.
IIVS offers the United States Pharmacopoeia (USP) cytotoxicity assay using Modified Eagles Medium (MEM) elution or agar overlay for medical device applications. The characteristics of the particular medical device, polymer, container, etc. determine which assay would be recommended. The MEM elution assay is designed to show the presence of toxic material eluted from a test sample as it affects L929 cells cultured in the presence of the extract. The degree of irritancy is determined microscopically in the percentage of cells deformed and lysed after exposure to the test material. In the agar overlay assay, test sample is placed onto the agar surface overlaid onto a L929 cell monolayer. Preventing direct damage while allowing diffusion of leachable chemicals from the sample. After treatment, the cells are exposed to neutral red dye to differentiate between the viable and stressed or lysed cells.
IIVS develops custom, cell-based assays measuring efficacy/potency of specialty chemicals, drugs, and biologics. Numerous bioassays have been and can be developed by IIVS to address specific requirements in chemical, pharmaceutical, personal care, and household products companies. As examples, in vitro models have been characterized and optimized for: collagen synthesis, biological activity, transepidermal penetration, test material efficacy, anti-inflammatory activity, and viral studies.
Prevalidation and Validation
IIVS has experience in managing programs for optimization of assay systems of specific interest to your company or organization, and in managing prevalidation and validation projects for groups of companies interested in bringing a system forward for regulatory acceptance. IIVS can be an active participant serving as the lead laboratory, providing the technology transfer, training, and standardized documentation (SOP and Protocol generation) for multi-laboratory projects. IIVS can prepare or assist in the preparation of data packages for submission either to ICCVAM or directly to a regulatory agency.