Flow Injection Analysis With UV Detection Versus Raman Spectroscopy for the Quantitative Analysis of Remdesivir

The quality and the security of preparations in hospital centres are essential to guarantee the patient's safety. The development of fast and efficient analytical methods is required to control the finished product before use. In this context, the study aimed to compare the performance and interchangeability of two spectral analytical methods: the flow injection analysis (FIA) with UV detection and the Raman spectroscopy for the quality control of preparation before use to quantify the remdesivir as a SARS-CoV-2 drug. A quantitative study of remdesivir was performed using clinically relevant concentration solutions ranging from 0.25 to 1.625 mg.mL⁻¹ in 0.9% NaCl. Samples were analysed by FIA-UV at 245 nm and by a handheld Raman spectroscopy at 785 nm. Quantitative models were developed using a calibration set (n = 45 samples) and optimized using a validation set (n = 27). An external validation test set (n = 58) was used to compare the two methods by a Bland–Altman plot. Partial least square regression was used to analyse Raman spectra, while univariate analysis was performed at 245 nm for FIA-UV. The regression coefficient was higher than 0.990 for both methods, and the root mean square error of prediction was 0.031 mg.mL⁻¹ for Raman spectroscopy. The Bland–Altman plot confirmed the interchangeability of the two methods and the potential of Raman spectroscopy to control remdesivir during clinical preparation in the hospital.