A rapid and simple assay for lamotrigine in serum/plasma by HPLC, and comparison with an immunoassay.
Monitoring serum/plasma concentrations of lamotrigine may be useful under certain circumstances. An HPLC column packed with strong cation-exchange (SCX)-modified microparticulate silica together with a 100% methanol eluent containing an ionic modifier permits direct injection of sample extracts. An HPLC-UV method developed using this principle for the measurement of serum/plasma lamotrigine is simple, sensitive and selective. The analysis time is less than 5 min. Intra- and inter-assay precision and accuracy meet acceptance criteria, and sample stability, and potential interferences from other compounds have been evaluated. There was good agreement with consensus mean results from external quality assessment samples (n = 32). Analysis of patient samples (n = 115) using the HPLC method and the Seradyn QMS® Lamotrigine immunoassay showed that the immunoassay over-estimated lamotrigine by 21% on average.
Morgan
Phillip E
PE
Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, Denmark Hill, London SE59RS, UK. phillip.morgan@nhs.net
Fisher
Danielle S
DS
Evers
Richard
R
Flanagan
Robert J
RJ
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002852:Chromatography, Ion Exchange; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D000077213:Lamotrigine; D016018:Least-Squares Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014227:Triazines / Q000097:blood*
D014227:Triazines; D000077213:Lamotrigine