Clinical Safety and Irritation Testing

Cumulative Irritation Evaluations

Nelson Labs Bozeman performs clinical evaluations in its Skin Technology Center for cumulative skin irritation in accordance with the guidance for industry titled “Skin Irritation and Sensitization Testing of Generic Transdermal Drug Products” (December 1999) controlled by the Center for Drug Evaluation and Research (CDER), part of the U.S. Food and Drug Administration (FDA).

Study Requirements:

The FDA guidance requires that the drug product and its vehicle (product without active principle) be tested, along with a high-irritancy control material, sodium lauryl sulfate (SLS; also known as sodium dodecyl sulfate, or SDS), and a low-irritancy control material, 0.9% saline, by applying small quantities to a single site on the skin of the upper back of 30 or more subjects each day for 21 days and occlusively patching each site while the applied material is wet.

If the testing is for an abbreviated new drug application (ANDA), in which bioequivalency data are necessary, a fifth material—the so-called innovator patch—is also tested, and the outcome for the test material is compared with that for the innovator, i.e. the product already approved to market to which the test material claims to be equivalent.

The degree of irritation at the sites is scored for degree of erythema, vesiculation, and peripheral extension each day prior to reapplication of the materials.

Face-Mask-Fit Testing

Why Perform Fit Testing on Your Face Mask?

Negative-pressure barrier face coverings (e.g., N95 respirators) are devices in which the air is purified by being pulled inwards through a filtration media during breathing. By design the efficacy of these devices relies on the air to pass solely through the incorporated filter. Air leaving through unintended gaps in the respirator’s seal compromises the face covering’s efficacy and may provide unsatisfactory protection.

In light of the recent COVID-19 pandemic and the subsequent increase in the use of facial coverings, ensuring the appropriate fit of face coverings has become not only a matter of personal safety but also public safety. Therefore, the ability of a respirator to fit appropriately on the diverse face shapes and sizes of any given community become critical to that community’s public health. For this reason fit testing of air-purifying, negative-pressure respirators should be conducted by manufacturers to measure how well the respirator seals to faces of different shapes and sizes. This testing can provide confidence to a respirator manufacturer that its respirator fully protects users of various face shapes and sizes.

Types of Fit Testing Available

25-Subject Full-Panel Study

Our most robust study follows the ASTM F3407 method and uses 25 test subjects to evaluate the capability of a face mask’s fit on a variety of face shapes and sizes. This study uses a standardized panel composition described by NIOSH. The exercises and pass/fail criteria of the test are identical to those required by OSHA for respirator users in the professional workplace for protection from hazardous gases and particulates.

10-Subject Data-Analysis Study

This clinical evaluation is a streamlined version of the full 25-subject panel, performed with only 10 study subjects. Unlike the 25-subject version, the 10-subject version does not offer an evaluation of pass/fail criteria; it does, however, provide empirical data on the device’s fit performance across the full standardized panel composition of various face shapes and sizes.

Design Analysis Evaluation

Nelson Labs Bozeman also offers design analysis to support fit efficacy. Our design-analysis service measures key components of the device’s design and evaluates the design’s probability of fit on a variety of face shapes and sizes.

Test Codes

If you would like to inquire about any of the services listed on this page, please submit the quote request form below.