Measurement of serum lamotrigine by high performance liquid chromatography using a phenyltriazine as internal standard
Article first published online: 23 FEB 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Drug Testing and Analysis
Special Issue: European Workplace Drug Testing Society 7th Symposium
Volume 4, Issue 2, pages 136–139, February 2012
How to Cite
Madhavaram, H., Woollard, G. A. and Couch, R. A. F. (2012), Measurement of serum lamotrigine by high performance liquid chromatography using a phenyltriazine as internal standard. Drug Test Analysis, 4: 136–139. doi: 10.1002/dta.255
- Issue published online: 24 FEB 2012
- Article first published online: 23 FEB 2011
- Manuscript Accepted: 13 DEC 2010
- Manuscript Revised: 2 DEC 2010
- Manuscript Received: 11 NOV 2010
- Internal standard;
Lamotrigine, an anti-epileptic drug with a phenyltriazine molecular structure, is commonly measured for therapeutic drug monitoring purposes by high performance liquid chromatography (HPLC) or gas liquid chromatography (GLC). A convenient internal standard is the structurally related phenyltriazine compound BWA725C previously obtainable from the Wellcome Foundation, UK. Irsogladine is also structurally similar to lamotrigine and was therefore tested as a possible replacement for BWA725C.
A GLC procedure with thermionic detection (NPD) has been utilized routinely for lamotrigine in our drug monitoring facility. Irsogladine was unsuitable, however, because the retention times of irsogladine and a co-prescribed drug, carbamazepine, were very similar. An HPLC method utilizing a Prodigy Phenomenex ODS3 column performed well using either of the internal standards. The pH of the mobile phase had a distinct impact on the spectra of lamotrigine and BWA725C. A mobile phase at pH 3, with detection at 225 nm was required to effectively resolve lamotrigine from sulthiame and irsogladine from phenobarbitone. Comparison of the HPLC and the existing GLC method with routine patient specimens (n = 43) gave an equation, y = 0.9382x + 0.8238, R2 = 0.9862. Irsogladine was found to be a suitable internal standard for an HPLC analysis of lamotrigine. Copyright © 2011 John Wiley & Sons, Ltd.