Examining green analytical chemistry approach for development of a gradient HPLC protocol for the simultaneous analysis of pregabalin and duloxetine hydrochloride in capsule dosage form

Green analytical methods have become an area of keen interest in the field of pharmaceutical analysis to safeguard both the operators’ health and the environment. The present work describes the systematic development of a green, simple, sensitive, and robust reversed-phase high-performance liquid chromatographic method for simultaneous quantitative analysis of pregabalin and duloxetine hydrochloride in capsules. The chromatographic separation was achieved on a Shim-pack Solar C₁₈ (250 mm × 4.6 mm, 5 µm) column. The proposed method used a mobile phase, comprising of di-potassium hydrogen phosphate buffer (pH 7.0; 20 mM) and acetonitrile delivered in a gradient mode. The separated analytes were monitored at 210 nm. Validation, as per the ICH Q2(R1) guidelines, endorsed the efficiency of the developed novel analytical method. Employing the optimized chromatographic conditions, pregabalin and duloxetine hydrochloride were well separated with retention times of 3.9 and 12.7 min, respectively. The linear ranges of duloxetine hydrochloride and pregabalin were between 10–40 µg/mL and 25–100 µg/mL, respectively. Greenness assessment of the developed method was evaluated using three different assessment tools viz. Analytical Eco-Scale, GAPI, and AGREE. This is the first analytical method to be developed for the simultaneous estimation of these drugs in pharmaceutical dosage form based on green chemistry principles. The developed method was applied for the simultaneous determination of pregabalin and duloxetine in capsule dosage form.