Impurity profiling of dapsone using gradient HPLC method

• Published in: Journal of pharmaceutical and biomedical analysis Vol. 198; p. 113982
• Main Authors: Leistner, Adrian, Holzgrabe, Ulrike
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 10-05-2021
• Subjects: Dapsone; Gradient HPLC; Impurity profiling; QqTOF identification; Dapsone; Gradient HPLC; QqTOF identification; Impurity profiling
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2021.113982

•Development and validation of a HPLC method for the impurity control of dapsone.•Replacement of the TLC related substances test by HPLC methodology.•Identification of an unknown impurity of the reference substance via. LC–MS/MS.
The quality control of active pharmaceutical ingredients (APIs) is a very important aspect for drug products entering the market. However, also for the well-established drugs, there ought to be a state-of-the-art impurity control. Some of the pharmacopoeial tests for related substances still make use of thin layer chromatography, even though selectivity and sensitivity are suboptimal. Here, we report on the development of a new gradient high performance liquid chromatography (HPLC) method for dapsone in order to replace the currently described pharmacopoeial TLC method. The separation of all relevant components was achieved on a C18 stationary phase (Waters XTerra® RP18 5 μm 4.6 × 250 mm) using a water-acetonitrile gradient. A limit of detection (LOD) of 0.02% was registered for all specified impurities. Additionally, within this study an “impurity of an impurity” was identified by means of LC–MS/MS.