A fast, reproducible and sensitive human-plasma HPLC-fluorescence method to quantify Carvedilol and the error function

A robust and sensitive bioanalytical method was developed and fully validated using reverse-phase High-Performance Liquid Chromatography (HPLC) with fluorometric detection for the quantitative analysis of carvedilol in a complex matrix (human plasma). The method demonstrated satisfactory performance within the therapeutic concentration range (3.91–125 ng/mL), showing good linearity (coefficient of variation, CV: 12.05%), accuracy (relative error, RE: 11.51%), and precision—both intra-day (CV: 8.31%) and inter-day (CV: 10.84%)—as well as a recovery rate of 89.3%. The lower limit of quantification (LLOQ) and the limit of detection (LOD) were 1.95 ng/mL and 0.98 ng/mL, respectively. Sample stability was confirmed for up to 24 hours under autosampler conditions. The method yielded a short retention time of 3.15 minutes, enabling high-throughput analysis. Once validated, an analytical error function, expressed as a standard deviation (SD), was calculated to determine the most appropriate data-weighting approach across the calibration range. The best-fitting function was linear: SD (ng/mL) = 0.322 + 0.086C. An Analytical GREEnness Metric Approach (AGREE) of the method obtained a score of 0.67, indicating a moderately green profile. Due to its simplicity, cost-effectiveness, and rapid turnaround, the method is well suited for routine clinical use and may serve as a practical tool for monitoring medication adherence in healthcare settings, including hospitals.