The target of this study is focused on the determination of terbinafine hydrochloride (TFHC) as antifungal drug. A
potentiometric method based on modified screen-printed and modified carbon paste ion-selective electrodes was
described for the determination of TFHC in different pharmaceutical and biological fluids. It is based on potentiometric
titration of TFHC using modified carbon paste (MCPE) and screen-printed (MSPE) as end point indicator sensors. The
influences of the paste composition, different conditioning parameters and foreign ions on the electrodes performance
were investigated and response time of the electrodes has been studied. The electrodes showed Nernstian response of
57.83±0.75, 59.06±0.69, 56.99±0.92 and 58.75±1.06 mV decade-1 in the concentration range of 3.8×10-7–1×10-2 and
1×10-7–1×10-2 mol L-1 for MCPE (electrode I and II) and MSPE (electrode III and IV), respectively. The electrodes were
found to be usable within the pH range of 3.0–9.0 and 4.0-9.0 exhibited a fast response time (about 9 and 11 s), low
detection limit of 3.8×10-7 and 1.0 ×10-7 mol L-1, long lifetime (70, 85 and 152, 166 days) for MCPE (electrode I and II)
and MSPE (electrode III and IV), respectively. The electrodes were successfully applied for the determination of TFHC
in pharmaceutical preparation and biological fluids (urine and serum). The results obtained applying these potentiometric
electrodes are comparable with British pharmacopeia. The method validation parameters were optimized and the method
can be applied for routine analysis of TFHC drug.