For the first time, clemastine was estimated in this work utilizing two validated resonance Rayleigh scattering (RRS) and fluorimetric methods. The methods relied on forming an association complex in an acidic medium between eosin Y reagent and clemastine. In the spectrofluorimetric approach, the investigated drug was quantified by quenching the fluorescence-emission intensity of eosin Y at 543.5 nm. The RRS method relied on enhancing the RRS spectrum at 331.8 nm, which is produced when eosin Y interacts with clemastine. Suitable conditions were established for the reaction to achieve maximum sensitivity. The linear values obtained from the spectrofluorimetric approach and the RRS method fall into the ranges of 0.2–1.5 µg mL^− 1 and 0.25-2.0 µg mL^− 1, respectively. It was established that the detection limits for these methods were 0.045 µg mL^− 1 and 0.059 µg mL^− 1, respectively. The developed methodologies yielded acceptable recoveries when used to estimate the quantity of clemastine in its pharmaceutical tablet dosage form. Regarding the use of greener solvents that were chosen, the suggested and reported methods were compared with the help of the Green Solvents Selecting (GSST) tool for assessing hazardous solvents to achieve sustainability. Furthermore, analytical Eco scale and comprehensive assessments of whiteness, blueness, and greenness were carried out utilizing Modified NEMI, ComplexGAPI, and AGREE evaluation tools. Additionally, recently developed tools such as BAGI and RGB 12 were applied to assess the blueness and the whiteness of the suggested methods.

这项工作首次利用两种经过验证的共振瑞利散射 (RRS) 和荧光方法对氯马斯汀进行了估计。该方法依赖于在酸性介质中曙红Y试剂和氯马斯汀之间形成缔合复合物。在荧光分光光度法中，通过猝灭 543.5 nm 处曙红 Y 的荧光发射强度来对所研究的药物进行定量。 RRS 方法依赖于增强 331.8 nm 处的 RRS 光谱，该光谱是曙红 Y 与氯马斯汀相互作用时产生的。建立了适合反应的条件以达到最大灵敏度。荧光分光光度法和RRS法获得的线性值分别在0.2-1.5 µg mL ^{- 1}和0.25-2.0 µg mL ^{- 1}范围内。确定这些方法的检测限分别为 0.045 µg mL ^{- 1}和 0.059 µg mL ^{- 1}。当用于估计其药物片剂剂型中氯马斯汀的量时，所开发的方法产生了可接受的回收率。关于所选择的绿色溶剂的使用，在绿色溶剂选择（GSST）工具的帮助下对建议和报告的方法进行了比较，以评估危险溶剂以实现可持续性。此外，利用 Modified NEMI、ComplexGAPI 和 AGREE 评估工具进行了分析生态量表以及白度、蓝色和绿色的综合评估。此外，还应用了最近开发的 BAGI 和 RGB 12 等工具来评估建议方法的蓝度和白度。