Suvarna Yenduri, Shashank H, Naga Prashant K
A very sensitive and eco-friendly second-derivative spectrofluorimetric method was developed for simultaneous analysis of hydrochlorothiazide (HCTZ), amlodipine besylate (AML), and telmisartan (TEL) in pharmaceutical products and human plasma. Native fluorescence of HCTZ (λex267/λem295 nm), AML (λex362/λem415 nm), and TEL (λex292/λem369 nm) was used together with fluorescence enhancement achieved through sodium lauryl sulfate micelles at optimum excitation/emission wavelengths for all other analytes being analyzed. Overlap of spectroscopic data was able to be resolved through second-derivative spectrofluorimetry without prior separation. Method validation was performed according to ICH Q2(R1) guidelines; results showed excellent linearity (R2 > 0.999) across a concentration range of 3-18, 2-10, and 10-50 ng/mL for HCTZ, AML, and TEL, respectively. Accuracy, precision and robustness were demonstrated with %RSD values below two. Application of the method to pharmaceutical product and spiked plasma samples gave satisfactory recoveries with minimal matrix interference. Assessment of method greenness was conducted using AGREE Prep, MoGAPI, AGSA, SAMI, Ma Tool, CACI, and WECA metrics, all of which indicate superior environmental sustainability. The proposed method is simple, fast, low-cost, ultra-sensitive, and suitable for routine quality control and/or bioanalytical analysis.