Transdermal drug delivery is a multifactorial process with variable penetration mechanisms. Adverse effects associated with nonsteroidal anti-inflammatory drugs’ (NSAIDs) use in treatment for joint and muscle diseases are sufficiently severe to consider topical application. A drug's lipophilicity, fraction unbound and permeability found in the viable skin are some of the physiochemical factors influencing the delivery mechanism of transdermal absorption. These and other variables play a role in determining if the drug reaches the deep tissues via direct penetration from dermal or systemic blood redistribution. Pharmacokinetic models have been developed to help elucidate penetration routes and efficacy for various drugs. Improvements in modes of transdermal delivery through active research projects including relevant animal models and human translational research may introduce advances in clinical development of treatments
