As spectrofluorimetric resonance Rayleigh scattering technique for determination of antianxiety drug with red acidic dye, application for dosage form and human plasma

The resonant Rayleigh scattering (RLS) spectroscopy technique was used to examine the interaction between venlafaxine hydrochloride (VNX) and red dye, also known as EOSIN Y. Eosin and VNX interacted in an acidic buffer solution to generate an ion pair, which was accompanied by an increase in RLS intensity recorded at 315 nm. Furthermore, estimates were made for the reaction’s change in free energy and the stability constant. Using EOSIN Y as a probe, a novel approach was created based on this interaction for the sensitive VNX analysis. The outcomes showed that this strategy had good selectivity even when concomitant chemicals were present. Over the range of 30–800 ng mL⁻¹ for VNX, the scattering intensity (ΔI_RLS) was linearly dependent on the concentration of VNX. The techniques could be appropriately applied to the VNX analysis in spiked human plasma and pharmaceutical formula since they were validated in accordance with ICH guidelines.