Trifluoperazine Nano‐Level Assay in Pharmaceutical Formulation Using a Green and Simple Spectrofluorometric Approach Based on Ion Pairing With Erythrosine B: Application to Content Uniformity With Greenness and Blueness Evaluation

Trifluoperazine (TFP) is an important phenothiazine derivative that has anti-adrenergic, anti-dopaminergic, and mild anti-cholinergic effects. It is used in the treatment of certain psychotic disorders and parkinsonism. TFP was determined using a simple, green, sensitive, and non-extractive spectrofluorimetric approach in bulk and pharmaceutical formulation. The basic principle of this technique is the association complex that could be formed between TFP and erythrosine B in an acidic environment. The complex formation quenched the intrinsic erythrosine B fluorescence that was monitored at 552 nm following excitation at 530 nm. The linear concentration range was 50-1400 ng mL^-1 with a respectable correlation coefficient (r = 0.9998). All factors influencing the production of the complex were investigated and adjusted. The LOD and LOQ were 15 and 46 ng mL^-1, respectively. For the validation criteria, the International Council on Harmonization (ICH) guidelines had been followed. It was possible to analyze TFP in bulk, tablet formulations, and evaluation of Stellasil tablet content uniformity using the proposed method with accurate, reproducible, and repeatable results. Finally, the greenness of the developed approach was assessed utilizing three advanced tools: the Eco-Scale, GAPI, and AGREE. In addition, the blueness of the approach was evaluated using a new tool called BAGI.