Armour Pharmaceutical Company

Reheis, Inc.

Reheis Chemical Company, Inc.

James F Kozischek

Rudolph Ferentchak

M Donner Martin, Jr

Jerome E Schwartz

Antiperspirant formulations are provided in which water-immiscible adjuvants are encapsulated in thick-walled, hollow, substantially spherical particles of antiperspirant active, which is preferably a water-soluble compound or complex of a polyvalent metal or metals. The thick-walled particles resist rupture during normal handling and application of the antiperspirant formulation and provide slow release of the encapsulated adjuvant when the antiperspirant shell dissolves in perspiration. The adjuvant may be a fragrance, an antibacterial, antimicrobial or antifungal agent, a deodorant, or other dermatological preparation. The encapsulation is accomplished by emulsifying the adjuvant in an aqueous solution of the antiperspirant active, and spray drying the material in such a manner as to produce thick-walled, spherical particles with the liquid adjuvant in the hollow centers.

Encapsulation of adjuvants within antiperspirant actives

Spray dried thermosetting resin powders in an intermediate polymeric stage are produced in the form of hollow, thick-walled, macrospherical particles having a bulk density greater than about 35 lbs/ft.sup.3 and having particle diameters predominantly in the range of about 10 to 74 microns, preferably averaging about 30 microns in diameter with greater than 90% of the particles being in the 10 to 74 micron range. The powder is produced by centrifugal atomization of a concentrated resin solution through a porous sintered metal filter in a spray drying chamber, preferably without diluting or preheating the solution and without heating the resinous material above about 160.degree. F. during spray drying. The particles are advantageously used in the dry process molding of consolidated wood fiber structures, such as waferboard and chipboard, in which wood fiber elements mixed with the resin powder are consolidated under heat and pressure sufficient to cause the powder to melt, flow and cure.

Thermosetting resin binder particles and methods for making waferboard

A process and improved apparatus are provided for producing macrospherical particles. The particles themselves have increased wall thicknesses and higher densities than particles produced by conventional means and are thus not subject to deep lung penetration. The produced particles are also of controlled (narrow) particle size distribution. Such particles are particularly well adapted for use as anti-perspirants. The process for producing the particles comprises providing a solution containing the materials from which the particles are made, dispersing the solution along a plurality of radially disposed bristles by centrifugal force into discrete liquid droplets and drying the solution droplets in a stream of heated air. The improved apparatus comprises mounting a rotatable atomizer having a plurality of bristles inside a spray drying chamber.

Production of macrospherical particles

A process and apparatus are provided for making hollow macrospherical particles. The particles themselves are particularly adapted for use as anti-perspirants. The particles have a diameter between about 10 and 74 microns, preferably predominating between 15 and 44 microns, and a greater than unit density. As such, they are not subject to deep lung penetration. The process for producing the particles comprises providing a solution containing the materials from which the particles are made, diffusing the solution through small pores by centrifugal force such that the resulting hollow particles have a diameter greater than the pore diameter, and drying the solution droplets in a stream of heated air. The apparatus for producing the macrospherical particles comprises a centrifugal atomizer having a porous sintered metal filter ring which is rotated inside a spray drying chamber. The filter is treated to produce hollow macrospheres having substantially smooth outer walls of such thickness that they can withstand normal shipment and handling without significant fragmentation.

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Belvidere, NJ, United States of America

James F Kozischek