An Analysis of the Ortho Evra Birth Control Patch

Abstract

The Ortho Evra Birth Control Patch is an effective alternative method of birth control. It releases two drugs, norelgestromin and ethinyl estradiol, and these two drugs diffuse through a person?s skin and into their bloodstream. In order to analyze this process, we developed a 2-D, axisymmetric model of the diffusion of norelgestromin from the patch and through the skin. Through the use of a sensitivity analysis to determine the correct patch diffusivity, we were able to get an accurate representation of the physical process. We then modeled what would happen if the patch were removed for various periods of time, and we were able to determine that if the patch were removed for 24 hours or less, no significant disruption to the delivery of the drugs would occur. Finally, we also ran a simulation of wearing two different patches over the course of two weeks, and we determined that the concentration would normally encounter periodic rises and falls over the two-week period.