How do companies do manufacturing of a transdermal patch?

A transdermal patch is used to deliver medication directly through the skin in a time release formula. One patch may be good for 24 up to 72 hours, depending on the medication.

Transdermal "units" (one patch) are made in two layers. The innermost layer contains a special formula of glue on one side. The glue helps it stick to skin without destroying the skin. In processing, a special plastic is laid over the glue--this plastic is removed before placing it on a patient's skin. On the other side of this layer, manufacturing machines place a gob of semi-liquidy medication. When the top layer, another piece of special porous patch, is placed on top, it forms a pocket between the innermost and outermost layers. All 4 edges of the top / outer and bottom / innermost porous layers are sealed together, so you have one patch.

Each patch is specially packaged inside a foil pouch. The patient rips open the pouch, removes the patch, takes off the plastic layer on the back, and presses the pouch onto the skin.

The manufacture of patches, like all medications, is under strict government rules for safety.