US 12,083,200 B2
Zinc oxide particles, photostable UV filters, and methods of use thereof
Harry W. Sarkas, Shorewood, IL (US); and Christopher C. Boffa, Joliet, IL (US)
Assigned to Nanophase Technologies Corporation, Romeoville, IL (US)
Filed by Nanophase Technologies Corporation, Romeoville, IL (US)
Filed on Apr. 24, 2023, as Appl. No. 18/138,583.
Application 18/138,583 is a continuation of application No. 17/186,518, filed on Feb. 26, 2021, granted, now 11,672,744.
Claims priority of provisional application 63/047,856, filed on Jul. 2, 2020.
Prior Publication US 2023/0363990 A1, Nov. 16, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. A61K 8/27 (2006.01); A61K 8/02 (2006.01); A61Q 17/04 (2006.01); B82Y 5/00 (2011.01); B82Y 30/00 (2011.01); B82Y 40/00 (2011.01)
CPC A61K 8/27 (2013.01) [A61K 8/0241 (2013.01); A61Q 17/04 (2013.01); A61K 2800/413 (2013.01); A61K 2800/522 (2013.01); A61K 2800/622 (2013.01); A61K 2800/63 (2013.01); A61K 2800/651 (2013.01); A61K 2800/805 (2013.01); B82Y 5/00 (2013.01); B82Y 30/00 (2013.01); B82Y 40/00 (2013.01)] 20 Claims
OG exemplary drawing
 
1. Zinc oxide particles, wherein the particles have:
an O:Zn ratio of at least 0.999,
an average particle size of 10 to 300 nm,
a sufficient concentration of oxygen vacancies and zinc vacancies to give a dispersion of the particles in C12-C15 alkyl benzoate an orange to tan color corresponding to a ΔE value of at least 15 in a Dispersion Color Test;
wherein the ΔE in the Dispersion Color Test is calculated as:
ΔE=√(L*2−L*1)2+(a*2−a*1)2+(b*2−b*1)2,
wherein L*2, α*2, and b*2 are the color coordinates of a zinc oxide particle test sample and wherein L*1=99.47, α*1′=−0.16, and b*1=−0.17 correspond to color coordinates of a white reference tile; and
wherein the particles contain no aggregates and have no detectable particles 500 nm or larger, using laser light scattering on a number-weighted basis.