In the last decades, polymeric systems were essayed and applied successfully as vehicles for transdermal delivery devices of active principles. Applications in contraception, pain control, and smoking cessation are already frequent. A crucial aspect in the development of new formulations is the maintenance of the therapeutic drug concentration range for long periods. Recognizing this topic as interesting and challenging, simple models to describe drug release from a transdermal device were developed with the purpose to perform a parametric sensitivity analysis. Assuming drug diffusion within the polymeric delivery system as the dominant mechanism the models were developed and implemented. Transdermal patches made of the single adhesive material layer (the drug reservoir) and made of two layers were considered during drug release modeling to the skin. The sensitivity analysis of parameters such as drug diffusion coefficient and initial drug concentration brought insight into drug transfer process inside the patches, revealing itself as a useful tool in the optimization of drug delivery devices.