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  5. OTC Aerosol Spray Products – Particle Size Distribution
  1. The FDA Science Forum

2021 FDA Science Forum

OTC Aerosol Spray Products – Particle Size Distribution

Download the Poster (PDF; 0.99 MB)
Authors:
Poster Author(s)
Cao, Leo N.Y., FDA/CDER; Holtgrewe, Nicholas, FDA/CDER; Bahde, Robert, FDA/CDER; Adah, Steven, FDA/CDER; Keire, David, FDA/CDER; Liu, Xiaofei, FDA/CDER
Center:
Contributing Office
Center for Drug Evaluation and Research

Abstract

Poster Abstract

Background

Unintended inhalation of OTC spray/powder/aerosol drug products has placed importance on understanding characteristic particle size distributions in the sprayed products, which is crucial to determine lung deposition. There are little or no data on the toxicity of OTC spray ingredients inhaled into the lung. Because of this lack of data, FDA has previously attempted to limit lung exposure to spray ingredients by proposing limits on the size of particles dispensed from consumer containers such as finished spray sunscreens in the February 26, 2019 proposed rule, Sunscreen Drug Products for Over-the-Counter Human Use (84 FR 6204). FDA is interested in learning more about the particle size distributions of sprays emitted from consumer spray products.

Purpose

Here, we intend to develop a real-time assessment method for the aerosol particle size distributions, between 15 nm and 20 µm, of 12 OTC sunscreen spray products.

Methods

A cylindrical environmental chamber (11-1/2" ID, 2 ft long) was designed and built for the simultaneous sampling of sunscreen sprays into real-time particle sizing instruments, including but not limited to: Scanning mobility particle sizer spectrometer (SMPS) and Aerodynamic particle sizer spectrometer (APS). A case study was also conducted to evaluate the effect of rapid evaporation of the sunscreen spray droplets or some other testing condition on the measured particle size distribution.

Results

The aerosol sampling and testing system for inhalation exposure assessment on OTC sunscreen spray products has been developed. The measured particle number concentrations for the sunscreen spray aerosols are from 8×10^3 to 3×10^5/cm^3. Most of the particles are in the sub-micron range. The mass concentrations are from 2 to 131 mg/m^3. The mass fraction for particles smaller than 1 ?m is from 0% to 8%, and smaller than 5 ?m is from 58% to 80%. More studies are needed to investigate analytical methods for the impact of these and other factors on the sunscreen particle size distribution measurements.

Conclusion

A real-time method for measurement of size distributions of OTC sunscreen spray products was developed to potentially provide data to better inform the proposed particle size requirements for OTC consumer spray products.

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Preview image of the scientific poster. For more information, please refer to the abstract or download the PDF version of the poster.

Download the Poster (PDF; 0.99 MB)

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