Not available,(S)-N-(2-(1-(3-ethoxy-4-methoxyphenyl)-2-(methylsulfonyl)ethyl)-1,3-dioxoisoindolin-4- yl)acetamide-D5,"Isotope labelled Apremilast , an oral phosphodiesterase 4 inhibitor is used in the treatment of psoriatic arthritis. ;Labeled Apremilast, intended for use as an internal standard for the quantification of Apremilast by GC- or LC-mass spectrometry.",Apremilast Stable Isotopes