Development and validation of a HPLC method for therapeutic monitoring of brivaracetam

Brivaracetam belongs to antiepileptic drugs and due to the interindividual variability, therapeutic drug monitoring is recommended, especially when used in polytherapy and in patients with altered pharmacokinetics. The aim of this study is to develop and validate a high-performance liquid chromatography (HPLC) method with a diode array detector (HPLC-DAD) that is suitable for therapeutic monitoring of brivaracetam and assess method's greenness.

High-performance liquid chromatography method was validated according to the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) and Clinical and Laboratory Standards Institute (CLSI) guidelines. Preparation of serum samples was performed by liquid-liquid extraction using ethyl acetate:hexane (1:1) with chloramphenicol as internal standard. Separation was achieved using a 5 µm 4.6 x 250 mm C18 Shim-pack GIST column with the mobile phase consisting of a 50 mM phosphate buffer (pH = 4.5) and organic mixture of acetonitrile and methanol (8/3; v/v). Brivaracetam is quantified at 210 nm. AGREEprep was utilized for the method's greenness scoring.

The developed HPLC-DAD method is linear over a concentration range of 0.25-20.00 µmol/L. Repeatability was lower than 7.20%, intermediate precision was lower than 8.30%, and within-laboratory precision was lower than 10.50%, except for the values at the lower limit of quantification (0.25 µmol/L) which were still below 20.00%. Bias was lower than ± 10.60%. The method displays very high specificity at 210 nm. The result for method greenness was 0.4.

The validation parameters were within the acceptance criteria of the ICH and CLSI guidelines. The developed method is simple, selective, reproducible, more sensitive than other published HPLC methods and suitable for the therapeutic drug monitoring of brivaracetam.