US 11,052,231 B2
Microarray for delivery of therapeutic agent and methods of use
Zhongli Ding, Sunnyvale, CA (US); Guohua Chen, Sunnyvale, CA (US); Ashutosh Shastry, Santa Clara, CA (US); Robert Wade Worsham, Cupertino, CA (US); and Parminder Singh, Union City, CA (US)
Assigned to Corium, Inc., Grand Rapids, MI (US)
Filed by CORIUM INTERNATIONAL, INC., Menlo Park, CA (US)
Filed on Dec. 20, 2013, as Appl. No. 14/137,899.
Claims priority of provisional application 61/745,513, filed on Dec. 21, 2012.
Prior Publication US 2014/0180201 A1, Jun. 26, 2014
Int. Cl. A61M 37/00 (2006.01); A61K 9/00 (2006.01); B29C 70/78 (2006.01); B81C 1/00 (2006.01); B29C 43/02 (2006.01)
CPC A61M 37/0015 (2013.01) [A61K 9/0021 (2013.01); B29C 43/021 (2013.01); B29C 70/78 (2013.01); B81C 1/00357 (2013.01); A61M 2037/0046 (2013.01); A61M 2037/0053 (2013.01); B29C 2043/025 (2013.01)] 35 Claims
OG exemplary drawing
 
1. A microstructure apparatus comprising:
a backing having a first surface and a second surface opposed thereto;
a microstructure array comprising a plurality of microstructures extending outwardly from the first surface of the backing;
the plurality of microstructures comprising a biodegradable distal layer and at least one proximal layer positioned between the distal layer and the first surface of the backing;
the distal layer comprised of at least one therapeutic agent and a polymer matrix comprising at least one polymer, wherein:
(i) the at least one polymer is a hydrophobic polymer that is insoluble or substantially insoluble in aqueous solvents, wherein the polymer matrix is comprised of about 50-100% of the hydrophobic polymer, thereby imparting a brittle character to the distal layer and promoting detachment of at least a portion of the distal layer; or
(ii) the at least one polymer is at a concentration in a polymer casting solution used to form the distal layer of the plurality of microstructures that is at or below an entanglement concentration (CE) for the at least one polymer, thereby promoting detachment of at least a portion of the distal layer; and
wherein the distal layer formed from the polymer matrix having the configuration of (i) or (ii) is configured such that at least the portion of the distal layer detaches from the plurality of microstructures upon insertion of the microstructure array into skin.