Dioctadecyldimethylammonium bromide (DODAB), is a double chain synthetic cationic lipid that conforms the membrane-like bilayer structure and has found widespread use in several biomedical applications. Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most widely used drugs for their pain reducing and anti-inflammatory action. Different NSAIDs, having similar chemical structure, show different biological impact and their therapeutic effects. The mechanisms leading to these differences should be related to their interaction with the biological membranes which can change the structure and dynamics of the membrane system significantly. To investigate the change in dynamical behavior of lipid molecules due to drugs-membrane interaction, we would like to perform the QENS study on the DODAB membrane with three prominent NSAIDs namely aspirin, ibuprofen and indomethacin.