Background: Terbinafine is an allylamine antifungal that is effective against many
fungi, dermatophytes and moulds. Analytical methods are required for the determination of
terbinafine in biological fluids to perform therapeutic drug monitoring and pharmacokinetic
Objective: The aim of this study was to develop and validate a novel and fast method combining
dilute and shoot approach and high-performance liquid chromatography coupled with photodiode
array detection for the determination of terbinafine in human urine.
Methods: Chromatographic parameters including mobile phase composition, pH, flow rate and
injection volume were assessed and optimized. The separation of terbinafine and naproxen
(internal standard) was achieved within 3 min using a C18 core-shell column (Raptor ARC-18, 100
x 4.6 mm, 2.7 μm) under isocratic conditions. Samples were eluted from the column at the flow
rate of 1.4 mL/min using a mobile phase containing 0.2% triethylamine in water (pH 3.4 with
formic acid): acetonitrile (45:55, v/v).
Results: The presented technique was linear in the range of 25-2000 ng/mL. Intra- and inter-day
reproducibility at four quality control levels (25, 200, 750 and 1500 ng/mL) were less than 7%,
with relative errors ranging from -5.40% to 5.91%. The limit of detection was 12.60 ng/mL. The
developed method has three main advantages compared to existing methods: simplicity and
greenness of sample preparation, use of core-shell column and short analysis time.
Conclusion: The results of this study indicate that the combination of dilute and shoot approach
and core-shell column can be regarded as an advantageous application for the fast determination of
terbinafine in the urine.