HPLC-SPE-NMR in pharmaceutical development: capabilities and applications.
High-performance liquid chromatography-solid phase extraction-NMR spectroscopy (HPLC-SPE-NMR) has recently become commercially available and has been evaluated with regard to its applicability in a pharmaceutical environment. The addition of an automated SPE unit to an HPLC-NMR system for peak trapping results in an improved NMR signal-to-noise ratio (S/N) and also has other practical advantages. The trapping efficiency is shown to depend on compound polarity and is highest for compounds eluting late on reversed-phase HPLC systems. Multiple peak trapping further increases the S/N, again with the best results for less polar compounds. For polar compounds, multiple peak trapping resulted in no S/N gain as the amount of material retained on the SPE cartridge was equivalent to that from a single injection. When compared with conventional HPLC-NMR, a S/N gain of up to five-fold could be achieved for some compounds in a single trapping step. A major advantage of the technique is the independence of the chromatographic step from the NMR step, resulting in greater versatility than conventional HPLC-NMR in the HPLC solvents and NMR solvents that can be used. Practical applications from both drug metabolite and drug impurity identification are presented.
Sandvoss
Martin
M
DMPK Structural ID Group, GlaxoSmithKline R & D, Ware, UK. martin.x.sandvoss@gsk.com
Bardsley
Ben
B
Beck
Tony L
TL
Lee-Smith
Emma
E
North
Stephanie E
SE
Moore
Peter J
PJ
Edwards
Andrew J
AJ
Smith
Richard J
RJ
D000097:Acetonitriles / Q000737:chemistry; D000146:Acids, Carbocyclic / Q000032:analysis / Q000737:chemistry; D000818:Animals; D001646:Bile / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004285:Dogs; D007659:Ketones / Q000032:analysis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry; D051381:Rats; D012680:Sensitivity and Specificity; D012997:Solvents / Q000737:chemistry
D000097:Acetonitriles; D000146:Acids, Carbocyclic; D007659:Ketones; D004364:Pharmaceutical Preparations; D012997:Solvents; C032159:acetonitrile