Green and white analytical approach for parallel quantification of gabapentin and methylcobalamin in medicinal products using inventive RP-HPLC technique

A simple, selective, and environmentally sustainable RP-HPLC method was developed for simultaneous quantification of gabapentin (GAB) and Methylcobalamin (MET) in pharmaceutical products. Separation was achieved on a Zorbax Eclipse C8 column (150 × 4.6 mm, 3.5 μm) using a green mobile phase of potassium phosphate buffer (pH 6.9)/acetonitrile (95:5 v/v) at 2.0 mL/min, with detection at 210 nm. Total analysis time was 10 min with 100 µL injection volume. The method showed excellent linearity (3-50 µg/mL; R² > 0.9998), LODs (0.60-0.80 µg/mL), and LOQs (2.00-2.50 µg/mL). Environmental sustainability was validated by multiple metrics: AGREE (0.70), AGREEprep (0.71), and Analytical Eco-Scale (80), confirming superior greenness. Forced degradation studies demonstrated stability-indicating capability per ICH guidelines. This eco-friendly approach provides a reliable solution for quality control of GAB/MET formulations while minimizing environmental impact.