Stability Study for EMLA Cream Using In Vitro Percutaneous Absorption

EMLA Cream (lidocaine 2.5% and prilocaine 2.5%) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine. It is a numbing cream that can be placed on the skin to provide pain relief, and used to numb an area before placing an IV, drawing blood, or giving injections. A typical stability study is conducted by the assay of API in the drug product, but the different product qualities may affect penetration. To evaluate penetration, in vitro human cadaver skin model using Franz diffusion cells is used to determine product equivalence. In this study, we evaluate the product equivalence at different stability time points between RLD and test products.