Performance Demonstration of a Frugal and Green UV–Visible Spectrophotometric Method for the Direct Determination of Artemether in Artemether–Lumefantrine Tablets

Introduction The proliferation of poor-quality antimalarials poses a severe threat to public health in sub-Saharan Africa. Systematic quality control requires accessible and eco-friendly analytical methods. Purpose This study documents the performance demonstration and validation of a direct, green, and frugal UV–Visible spectrophotometric method for the quantification of artemether in fixed-dose combination tablets without chemical derivatization. Methods Selective separation was achieved at 255.0 nm using a 0.5% (w/v) aqueous sodium lauryl sulfate (SLS) micellar matrix, which encapsulates hydrophobic artemether while selectively precipitating the masking co-formulated lumefantrine. Results Validated through the total error strategy via a 95% β-expectation accuracy profile over a working range of 28.0–36.0 µg/mL (n = 45), the global Ordinary Least Squares (OLS) calibration model demonstrated excellent predictability (y = 0.0208x + 0.0627, R2 = 1.000). Metrological sensitivity boundaries yielded a limit of detection (LOD) of 0.5187 µg/mL and a limit of quantification (LOQ) of 1.5718 µg/mL. Method trueness was confirmed with mean recoveries ranging from 98.71% to 100.34% and relative systematic bias between −1.29% and +0.34%. Random error components evaluated via ANOVA showed high precision, with repeatability and intermediate precision coefficients of variation strictly below 0.181% and 0.205%, respectively. Conclusion Field application to commercial tablet samples collected in Kisangani established compendial compliance within the 90.0%–110.0% pharmacopeial limits (98.75%–106.76%). Although its resolution is lower than compendial HPLC-UV methods, this low-cost, solvent-free protocol serves as an effective frontline screening tool for decentralized surveillance laboratories in low- and middle-income countries.