Microarray for delivery of therapeutic agent and methods of use

A microstructure apparatus comprising:

• a substrate having a first surface and a second surface opposed thereto;
• a microstructure array comprising a plurality of microstructures affixed to the first surface of the substrate and extending outwardly therefrom;
• the microstructures comprising of a biodegradable distal layer and a proximal layer positioned between the distal layer and the first surface of the substrate;
• the distal layer comprised of at least one hydrophobic polymer and at least one therapeutic agent, and
• wherein at least a portion of the distal layer detaches readily upon insertion of the array into skin.

A microstructure apparatus comprising:

• a backing having a first surface and a second surface opposed thereto;
• a microstructure array comprising a plurality of microstructures affixed upon the first surface of the backing and extending outwardly therefrom;
• the microstructures comprising of a biodegradable distal layer and a proximal layer positioned between the distal layer and the first surface of the backing;
• the distal layer is comprised of at least one polymer and about 1-99% of a therapeutic agent;
• and
• wherein at least a portion of the distal layer detaches readily upon insertion of the array into skin,

A microstructure apparatus comprising:

• a backing having a first surface and a second surface opposed thereto;
• a microstructure array comprising a plurality of microstructures affixed upon the first surface of the backing and extending outwardly therefrom;
• the microstructures comprising a biodegradable distal layer and a proximal layer positioned between the distal layer and the first surface of the backing;
• the distal layer comprised of at least one polymer and a therapeutic agent, the at least one polymer having a glass transition temperature (Tg) at least above about body temperature;
• and
• wherein at least a portion of the distal layer detaches readily upon insertion of the array into skin.

A microstructure apparatus comprising:

• a backing having a first surface and a second surface opposed thereto;
• a microstructure array comprising a plurality of microstructures affixed upon the first surface of the backing and extending outwardly therefrom;
• the microstructures comprising a biodegradable distal layer and a proximal layer positioned between the distal layer and the first surface of the backing;
• the distal layer comprised of at least one polymer having a molecular weight between about 1-100K Da and a therapeutic agent;
• and
• wherein at least a portion of the distal layer detaches readily upon insertion of the array into skin.

A microstructure apparatus comprising:

• a backing having a first surface and a second surface opposed thereto;
• a microstructure array comprising a plurality of microstructures affixed upon the first surface of the backing and extending outwardly therefrom;
• the microstructures comprising a biodegradable distal layer and a proximal layer positioned between the distal layer and the first surface of the backing;
• the distal layer comprised of at least one polymer and a therapeutic agent;
• and
• wherein at least about 10-100% of the distal layer detaches readily upon insertion of the array into skin.

A microstructure apparatus comprising:

• a substrate having a first surface and a second surface opposed thereto;
• a microstructure array comprising a plurality of microstructures affixed upon the first surface of the substrate and extending outwardly therefrom;
• the microstructures comprising a biodegradable distal layer and a proximal layer positioned between the distal layer and the first surface of the substrate;
• the distal layer comprised of at least one polymer and a therapeutic agent, the distal layer having a first cross-dimensional diameter that is larger than a second cross-dimensional diameter;
• and
• wherein at least a portion of the distal layer detaches readily upon insertion of the array into skin.

A method of making a microstructure apparatus comprising:

• dissolving or suspending a therapeutic agent in a solvent to form a therapeutic agent solution or suspension;
• dissolving at least one polymer in a solvent to form a polymer solution;
• mixing the therapeutic agent solution or suspension and the polymer solution or suspension to form a polymer matrix solution or suspension;
• dispensing the polymer matrix solution or suspension on a mold having an array of microstructure cavities;
• followed by pressurization;
• removing excess solution or suspension polymer matrix on the mold surface;
• and
• drying the matrix;
• and
• dispensing a basement or backing layer on the mold surface;
• and
• drying the basement or backing layer.