Optimisation of a high-efficiency liquid chromatography technique for measuring lamotrigine in human plasma

Objective

The purpose of this study was to optimise the HPLC-UV bio-analytical method currently used by the Salamanca University Clinical Hospital for determining lamotrigine plasma levels.

Material and methods

The developed HPLC-UV analytic technique currently in use was shown to be linear, exact and precise, and suitable for use in routine monitoring of lamotrigine levels. The drawback of this method has always been the time required for analysing samples, so our aim was to improve on that elapsed time.

That improvement involved using a different chromatographic column from the one used up until now. We replaced the column that was normally used (Kromasil−100C18−5 μm−15^*0.4 cm with a LiChroCART-RP18e−3 μm−5.5^*0.4 cm); in both cases, a liquid-liquid extraction was performed and the same sample extraction protocol was followed.

Results

Both validation methods showed that the two column types are valid for routine lamotrigine monitoring.

Conclusion

The decrease in retention time, in addition to a lower quantification limit and better precision and accuracy parameters obtained with the LiChorCART column, suggest that this unit is ideal for use in clinical practice because it enables a large number of determinations to be performed in less time and the greater precision of LTG measurements.