Comparision of high-resolution gas chromatography and high-performance liquid chromatography for simultaneous determination of lamotrigine and carbamazepine in plasma

Rapid, simple and sensitive methods have been devised for simultaneous determination of lamotrigine (LTG) and carbamazepine (CBZ) in microsamples of human plasma by high-performance liquid chromatography (HPLC) and high resolution gas chromatography (HRGC); both methods have been validated and compared. The HPLC method was more sensitive than HRGC for both drugs, LTG and CBZ. The lowest quantitation limits (LOQ) of plasma LTG concentrations were 0.1 mug.mL(-1) (HPLC) and 0.5 mug.mL(-1) (HRGC); for CBZ they were 0.1 mug.ml(-1) (HPLC) and 0.25 mug.mL(-1) (HRGC). Both methods, are sensitive enough to work with microsamples at subtherapeutic, therapeutic and toxic concentrations, being reliable and practical for routine therapeutic monitoring of LTG. The HPLC method proposed is suitable also for pharmacokinetic studies orchid patient, routine therapeutic-drug monitoring where there is a need for sensitive methods and small sample sizes.