Eco-friendly RP-HPLC method for determination of diazepam in coated tablet

A new eco-friendly RP-HPLC method for determining diazepam in coated tablets was developed and validated. The separation was achieved on a Lichrosper® 100 RP-18 (250 mm × 4 mm, 5 µm particle size) using the isocratic elution mode with a mobile phase composed of a mixture of water (H2O) and ethanol (EtOH) in a 40:60 (v/v %) ratio and a flow rate of 1.0 mL/min. The injection volume was 10 μL, and the detection wavelength was set at 254 nm. The column temperature was maintained at 35 ºC. The method was validated according to the ICH guideline, emphasizing selectivity/specificity, linearity, sensitivity, accuracy, precision, and robustness. The analytical method greenness score and Eco-scale approach were used for the method’s greenness assessment. The method was applied to determine the assay of diazepam in coated tablets and the uniformity of dosage units by content uniformity. Applying the method proposed in this study in the pharmaceutical industry is considered environmentally sustainable. It would bring benefits in terms of a safer working environment and reduction of toxic waste formation without compromising the reliability of the analytical results.