Selective Removal of a Pharmaceutical Process Impurity Using a Reactive Resin

Abstract

A low‐level (0.5%), but troublesome, aldehyde impurity in a pharmaceutical product was conveniently removed from an existing process stream by employing a reactive, polystyrene‐based sulfonylhydrazine resin. Selection of this resin resulted from screening a number of adsorbents and reactive resins using a high throughput LC–MS approach. The sulfonylhydrazine resin was able to quickly remove an impurity from an existing, highly concentrated, product stream in DMF at a level of 20 mg resin for each gram of product. The material obtained from such treatment showed a greatly improved impurity profile, with an 85% reduction in the level of the aldehyde impurity and without introduction of additional impurities.

Keywords:

• Reactive resin
• Scavenger resin
• Selective adsorbents
• Adsorbent screening
• LC‐MS screening
• Flow injection analysis