Micellar electrokinetic chromatographic method for the dabrafenib determination in biological samples.

Two different micellar electrokinetic chromatographic methods to determine dabrafenib in urine and serum, both using borate buffer (pH 9.2, 20 mM) and SDS as separation electrolyte, are developed and validated. The analyses were carried out in a fused-silica capillary of 75 µm of internal diameter and total length of 47 and 37 cm for urine and serum determination, respectively. The detection of the target compound was performed at 227 nm in urine samples and at 251 nm in serum samples. The linearity range was from 1 to 21 mg/L of dabrafenib in urine and from 2 to 40 mg/L in serum. In all cases, inter- and intraday RSDs were <4%. Sample preparation of serum samples consists of an only step of 1:1 dilution with water before its injection in the electrophoretic system. These simple, sensitive, accurate, and cost-effective methods can be used in routine clinical practice to monitor dabrafenib concentrations in urine and serum of metastatic melanoma skin cancer patients.