US 12,350,382 B2
Method for preparing particles comprising metal oxide coating and particles with metal oxide coating
Ofer Toledano, Kfar Saba (IL); Haim Bar-Simantov, Netanya (IL); Nissim Bilman, Rehovot (IL); Leora Shapiro, Jerusalem (IL); Raed Abu-Reziq, Jatt Hamesholash (IL); Srikanth Sriadibhatla, Parisppany, NJ (US); William T. Sommer, Mendham, NJ (US); and Hanan Sertchook, Gedera (IL)
Assigned to Mayne Pharma LLC, Raleigh, NC (US)
Appl. No. 12/525,331
Filed by Ofer Toledano, Kfar Saba (IL); Haim Bar-Simantov, Netanya (IL); Nissim Bilman, Rehovot (IL); Leora Shapiro, Jerusalem (IL); Raed Abu-Reziq, Jatt Hamesholash (IL); Srikanth Sriadibhatla, Parisppany, NJ (US); William T. Sommer, Mendham, NJ (US); and Hanan Sertchook, Gedera (IL)
PCT Filed Feb. 3, 2008, PCT No. PCT/IL2008/000141
§ 371(c)(1), (2), (4) Date Oct. 6, 2009,
PCT Pub. No. WO2008/093347, PCT Pub. Date Aug. 7, 2008.
Claims priority of provisional application 60/898,700, filed on Feb. 1, 2007.
Prior Publication US 2010/0016443 A1, Jan. 21, 2010
This patent is subject to a terminal disclaimer.
Int. Cl. A61K 9/50 (2006.01); A01N 25/26 (2006.01); A01N 53/00 (2006.01); A61K 8/11 (2006.01); A61K 8/25 (2006.01); A61K 8/38 (2006.01); A61K 8/67 (2006.01); A61Q 19/00 (2006.01); B01J 13/02 (2006.01); B01J 13/22 (2006.01); C09C 3/06 (2006.01)
CPC A61K 9/5073 (2013.01) [A01N 25/26 (2013.01); A01N 53/00 (2013.01); A61K 8/11 (2013.01); A61K 8/25 (2013.01); A61K 8/38 (2013.01); A61K 8/671 (2013.01); A61Q 19/00 (2013.01); B01J 13/02 (2013.01); B01J 13/22 (2013.01); C09C 3/063 (2013.01); A61K 9/501 (2013.01); A61K 9/5021 (2013.01); A61K 9/5026 (2013.01); A61K 2800/412 (2013.01); Y10T 428/2991 (2015.01)] 11 Claims
 
1. A process for coating solid benzoyl peroxide consisting of:
(a) contacting, in an aqueous medium, the solid benzoyl peroxide with a cationic surfactant to obtain a dispersion of solid benzoyl peroxide having positive charges on its surface;
(b) adding an aqueous solution of a metal oxide salt to said dispersion, under conditions wherein said metal oxide salt precipitates onto the benzoyl peroxide, and acidifying to thereby form benzoyl peroxide that has a metal oxide layer coated thereon;
(b1) contacting, in an aqueous medium, the benzoyl peroxide coated with a metal oxide layer of the preceding step with a surface adhering additive being one or both of (i) a cationic polymer additive and (ii) a non-ionic additive, to obtain a dispersion of said coated solid benzoyl peroxide having an adhering additive on the surface thereof;
(b2) bringing the dispersion obtained in step (b1) into contact with an aqueous solution of a metal oxide salt, under conditions wherein said metal oxide salt precipitates onto the surface of said coated solid benzoyl peroxide, and acidifying to thereby form a solid benzoyl peroxide that has a further metal oxide layer coated thereon;
(c) repeating steps (b1) and (b2) at least 3 more times;
(d) after completion of step (c), aging the metal oxide coating at a temperature ranging between 4° C. and 90° C. and at a pH of 3-9 to form a coated solid benzoyl peroxide, wherein no aging step is conducted between repeated coating steps, but only after completion of step c; and, optionally,
(e) separating the coated, solid benzoyl peroxide from the aqueous medium and optionally rinsing and re-dispersing the coated, solid benzoyl peroxide in an aqueous medium.