Synthesis, Isolation, Identification and Characterization of a Drug-Excipient Interaction Degradation Impurity in Pramipexole by HPLC, LC/MS and NMR

A drug-excipient interaction impurity associated with the degradation process of pramipexole was isolated. The detected during stability study extended-release tablets. It found at a relative retention time 0.88 respect to pramipexole, using gradient HPLC-UV detection method described in USP. structure identified and fully characterized high resolution mass spectrometry, IR NMR techniques, as presented herein. (S)-N2-(methoxymethyl)-N6-propyl-4,5,6,7-tetrahydro-1,3-benzothiazole-2,6-diamine. mechanism its formation proposed. An efficient straightforward synthetic approach developed prepare confirm proposed pathway structure.