title: Development and validation of an assay method for the determination of trifluoroacetic acid in a cyclosporin-like drug.
abstract: An improved method for the assay of trifluoroacetic acid (TFA) in a cyclosporin-like drug substance is presented, based on ion chromatography with suppressed conductivity detection. Column fouling by the drug molecule is avoided by use of a sample preparation method in which the drug substance is precipitated at alkaline pH whilst the TFA remains in solution. The new method requires a smaller sample mass than a previous method based on headspace-GC-FID whilst achieving an improvement in sensitivity. During validation, the method's performance was found to be consistent with usual acceptance criteria, and the method was found to be robust in routine use.
authors: Quay Pharmaceuticals Limited, 28 Parkway, Deeside, Flintshire CH5 2NS, United Kingdom. m.powell@quaypharma.com
authors: Mark
authors: M
authors: Powell
authors: David
authors: D
authors: Humphreys
authors: Adam
authors: A
authors: Nagle
authors: Karen
authors: K
authors: Polowy
authors: Michael
authors: M
authors: Scannell
mesh_terms: D002852:Chromatography, Ion Exchange / Q000379:methods*; D016572:Cyclosporine / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D014269:Trifluoroacetic Acid / Q000032:analysis*
chemical_list: D012997:Solvents; D016572:Cyclosporine; D014269:Trifluoroacetic Acid