Substrate having properties of mammalian skin

A method of evaluating the interaction of at least one substance with mammalian skin, comprising the step of applying at least one substance to a substrate comprising:

• a) a first layer comprising polymeric first material, said first layer having a discrete first layer comprising a first surface, an opposing second surface and a polymeric first material, wherein the first layer has a thickness of from about 1 micron to about 1000 microns and a hardness of from about 10 to about 80 on the Shore A scale;
• b) a discrete second layer comprising a first surface, an opposing second surface, and a second material, wherein the second layer has a hardness of from about 1 to about 70 on the Shore OOO scale and a thickness of from about 0.001 cm to about 2.0 cm;
• c) a discrete third layer comprising a first surface and a third material, wherein the third layer has a hardness of from about 0 to about 90 on the Shore D scale;
• and wherein the second surface of the first layer is in substantially fixed and continuous contact with the first surface of the second layer;
• the second surface of the second layer is in substantially fixed and continuous contact with the first surface of the third layer;
• and wherein the ratio of the average thickness of the second layer to the average thickness of the third layer is from about 4:96 to about 25:75.

A method of product evaluation comprising the steps of:

• a) providing a first substrate comprising:
• i. a discrete first layer comprising a first surface, an opposing second surface and a polymeric first material, wherein the first layer has a thickness of from about 1 micron to about 1000 microns and a hardness of from about 10 to about 80 on the Shore A scale;
• ii. a discrete second layer comprising a first surface, an opposing second surface, and a second material, wherein the second layer has a hardness of from about 1 to about 70 on the Shore OOO scale and a thickness of from about 0.001 cm to about 2.0 cm;
• iii. a discrete third layer comprising a first surface and a third material, wherein the third layer has a hardness of from about 0 to about 90 on the Shore D scale;
• and wherein the second surface of the first layer is in substantially fixed and continuous contact with the first surface of the second layer;
• the second surface of the second layer is in substantially fixed and continuous contact with the first surface of the third layer;
• and wherein the ratio of the average thickness of the second layer to the average thickness of the third layer is from about 4:96 to about 25:75;
• b) providing a second substrate;
• c) contacting at least one of the substrates to an instrument capable of measuring frictional force;
• d) bringing the first substrate into contact with the second substrate;
• e) moving the first substrate with respect to the second substrate in a controlled manner while maintaining substantially continuous contact between the first substrate and the second substrate;
• and
• f) measuring the frictional force generated by the movement of the first substrate relative to the second substrate.

A method of product development, comprising the steps of:

• a) applying a substance to a substrate comprising:
• i. a discrete first layer comprising a first surface, an opposing second surface and a polymeric first material, wherein the first layer has a thickness of from about 1 micron to about 1000 microns and a hardness of from about 10 to about 80 on the Shore A scale;
• ii. a discrete second layer comprising a first surface, an opposing second surface, and a second material, wherein the second layer has a hardness of from about 1 to about 70 on the Shore OOO scale and a thickness of from about 0.001 cm to about 2.0 cm;
• iii. a discrete third layer comprising a first surface and a third material, wherein the third layer has a hardness of from about 0 to about 90 on the Shore D scale;
• and wherein the second surface of the first layer is in substantially fixed and continuous contact with the first surface of the second layer;
• the second surface of the second layer is in substantially fixed and continuous contact with the first surface of the third layer;
• and wherein the ratio of the average thickness of the second layer to the average thickness of the third layer is from about 4:96 to about 25:75;
• b) generating a first set of data by analyzing the substrate;
• and
• c) comparing the first set of data to a second set of data.

A method of simulating interactions with mammalian skin, comprising the steps of:

• a) providing a substrate comprising:
• i. a discrete first layer comprising a first surface, an opposing second surface and a polymeric first material, wherein the first layer has a thickness of from about 1 micron to about 1000 microns and a hardness of from about 10 to about 80 on the Shore A scale;
• ii. a discrete second layer comprising a first surface, an opposing second surface, and a second material, wherein the second layer has a hardness of from about 1 to about 70 on the Shore OOO scale and a thickness of from about 0.001 cm to about 2.0 cm;
• iii. a discrete third layer comprising a first surface and a third material, wherein the third layer has a hardness of from about 0 to about 90 on the Shore D scale;
• and wherein the second surface of the first layer is in substantially fixed and continuous contact with the first surface of the second layer;
• the second surface of the second layer is in substantially fixed and continuous contact with the first surface of the third layer;
• and wherein the ratio of the average thickness of the second layer to the average thickness of the third layer is from about 4:96 to about 25:75;
• b) performing an act on the substrate as may be performed on mammalian keratinous tissue.

A method of providing a calibration standard for instrumental measurements comprising the steps of:

• a) providing a substrate comprising:
• i. a discrete first layer comprising a first surface, an opposing second surface and a polymeric first material, wherein the first layer has a thickness of from about 1 micron to about 1000 microns and a hardness of from about 10 to about 80 on the Shore A scale;
• ii. a discrete second layer comprising a first surface, an opposing second surface, and a second material, wherein the second layer has a hardness of from about 1 to about 70 on the Shore OOO scale and a thickness of from about 0.001 cm to about 2.0 cm;
• iii. a discrete third layer comprising a first surface and a third material, wherein the third layer has a hardness of from about 0 to about 90 on the Shore D scale;
• and wherein the second surface of the first layer is in substantially fixed and continuous contact with the first surface of the second layer;
• the second surface of the second layer is in substantially fixed and continuous contact with the first surface of the third layer;
• and wherein the ratio of the average thickness of the second layer to the average thickness of the third layer is from about 4:96 to about 25:75;
• b) providing a first marking having a measured dimension on the substrate;
• c) performing an instrumental analysis of first marking to produce first data;
• d) performing the instrumental analysis of step (c) on mammalian keratinous having a second marking to produce second data;
• e) comparing the first data to the second data.

An article of commerce comprising:

• a) a substrate comprising:
• i. a discrete first layer comprising a first surface, an opposing second surface and a first material, wherein the first layer has a thickness of from about 1 micron to about 1000 microns and a hardness of from about 10 to about 80 on the Shore A scale;
• ii. a discrete second layer comprising a first surface, an opposing second surface, and a second material, wherein the second layer has a hardness of from about 1 to about 70 on the Shore OOO scale and a thickness of from about 0.001 cm to about 2.0 cm;
• iii. a discrete third layer comprising a first surface and a third material, wherein the third layer has a hardness of from about 0 to about 90 on the Shore D scale;
• and wherein the second surface of the first layer is in substantially fixed and continuous contact with the first surface of the second layer;
• the second surface of the second layer is in substantially fixed and continuous contact with the first surface of the third layer;
• and wherein the ratio of the average thickness of the second layer to the average thickness of the third layer is from about 4:96 to about 25:75;
• b) a communication to use said article of manufacture to simulate mammalian skin.