A sensitive voltammetric technique for the determination of avanafil (AVA) has been investigated at a carbon paste electrode modified with Zinc oxide nanoparticles and multi-walled carbon nanotubes (ZnO-NPs/MWCNT/CP). The study investigated the electrochemical behavior of AVA, and the morphology of the modified electrode was evaluated by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction patterns. The influence of different electrodes and the content of ZnO-NPs on the voltammetric behavior of AVA were evaluated. Square wave voltammetry was studied and a linear correlation resulted within the range of (1.3-16 μg ml −1 ) with correlation coefficient 0.999, LOD 0.342 μg ml −1 and LOQ 1.141 μg ml −1 . The proposed procedure was applied successfully for the determination of AVA with good recovery in commercial dosage form and human plasma. The technique was validated and found to be accurate and reproducible according to the ICH guidelines.

Aims: In this study, a simple, green, and rapid capillary zone electrophoresis (CZE) method coupled with a diode array detector (DAD) was applied for the analysis of avanafil (AVA) and dapoxetine hydrochloride (DAP) as a binary mixture using vardenafil (VAR) as an internal standard (IS) in pure form and pharmaceutical formulation. Methodology: The separation was done using fused silica capillary (58.5 cm total length, 50 cm effective length, and 50 μm internal diameter) and the running background electrolyte (BGE) was 100 mM acetate buffer at pH 3.6. During the separation process, the applied voltage was 30 KV, while the temperature was 25 °C. The sample injection was applied at a pressure of 50 mbar for 10 s, and detection was carried out at 210 nm for DAP and 248 nm for AVA and VAR. Results: Analysis of the tested drugs and the internal standard was carried out in less than 6.5 min, where the migration times were 4.29, 4.90, and 6.02 min for IS, DAP and AVA respectively. The proposed method showed linearity in the concentration range 5-80 and 5-70 μg/mL with correlation coefficients 0.9996 and 0.9999 for AVA and DAP respectively. The limit of detection (LOD) was 0.523 and 0.531 for AVA and DAP respectively, while the limit of quantification (LOQ) was 1.585 and 1.608 in respective order.  The Peak purity and identity in the proposed method were validated by DAD. Conclusion: The proposed CZE method was validated according to ICH guidelines and applied successfully for the estimation of AVA and DAP in their combined pharmaceutical preparation.