Transdermal Patch - Development

Development

Before these patches go into the market, they have to be carefully studied. One way to study these patches are through the use of Franz Diffusion Cell systems. This system is used to study the effects of temperature on the permeated amount of a specific drug on a certain type of membrane, which in this case would be the membrane that is used in the patches. A Franz Diffusion Cell system is composed of a receptor and a donor cell. In many of these research studies the following procedure is used. The donor cell is set at a specific temperature (the temperature of the environment ), while the receptor cell is set at different one (temperature of the body).

Different runs are performed using different temperatures to study the impact of temperature on the release of a certain medicament through a certain type of membrane. Although different concentrations of the medicament are used in this study, they do not affect the amount permeated through the membrane (the process is constant). From Chemical kinetics it’s concluded that these studies are zero order, since the concentration plays no role in the permeated amount through the membrane.

Some pharmaceuticals must be combined with substances, such as alcohol, within the patch to increase their ability to penetrate the skin in order to be used in a transdermal patch. Others can overwhelm the body if applied in only one place, and are often cut into sections and applied to different parts of the body to avoid this, such as nitroglycerin. Many molecules, however, such as insulin, are too large to pass through the skin without it being modified in some way. Several new technologies are being investigated to allow larger molecules to be delivered transdermally.