eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2026-03-20 19 1 558 570 /10.13005/bpj/3375 70336 article Khagga Bhavya Sri 1 Thandra Ambika 1 Dhilli Rao Gorja 2 Department of Pharmaceutical Analysis, RBVRR women’s college of pharmacy, Barkatpura Hyderabad, India. Department of Chemistry, Texila American University, Georgetown, Guyana Develop a simple, rapid, precise method and validate the method according to the ICH (Q2R1) and M10 guidelines. Using the 1-Naphthol reagent, which produces a coloured complex, a straightforward and sensitive spectrophotometric technique has been devised and validated for quantifying dabigatran etexilate mesylate (DAB) in both bulk and pharmaceutical dosage forms.DAB reacts with 1-naphthol in the presence of sodium nitrite and HCl with ammonium sulphamate, to form a green-colored complex which is a diazotization and azo coupling method. A sensitive UV-visible spectroscopy method determination of dabigatran in human plasma was developed and validated. 1ml aliquot was developed by protein precipitation with acetonitrile and validated. Beer’s law is obeyed in the concentration range of 8-62 µg/mL for dabigatranwith 1-Naphthol respectively with a correlation coefficient of 0.999. The limits of detection and quantification were 0.120µg/mL and 0.366 µg/mL for dabigatran. The recovery of accuracy was found to be 100.26%. Drug was quantified and was found to be 100.62%. The estimated calibration range of the method with plasma was 5–100 µg/ml. stability studies are performed and results are within limits. The recovery studies of accuracy and precision were studied.The superiority of this spectrophotometric technique has been demonstrated due to its low solvent concentration, lack of extraction stages, specificity, and sensitivity. A UV-visible technique that is sensitive, easy to use, and affordable was created and verified for the measurement of DAB in human plasma and pharmaceutical dosage form. https://biomedpharmajournal.org/vol19no1/quantification-of-dabigatran-in-spiked-plasma-bulk-and-formulation-using-1-naphthol-as-per-ich-guidelines-by-uv-visible-spectrophotometer/ Dabigatran Etexilate Mesylate (DAB) 1-Naphthol Plasma Stability studies UV-visible spectrophotometer