Eco-Friendly UV/Vis Spectrophotometric Determination of an Anticonvulsant and Cobalamin-Based Supplement in Bulk and Dosage Forms

A simple, precise, accurate, and economical UV spectrophotometric method was developed for the simultaneous estimation of lacosamide and cobalamin in bulk and tablet dosage forms. The method was validated as per ICH guidelines for parameters including linearity, accuracy, precision, robustness, and sensitivity. Both drugs followed Beer-Lambert’s law in the concentration range of 0.1–0.9 mg/mL for lacosamide and 0.1–0.9 µg/mL for cobalamin, with a correlation coefficient of 0.991. The method showed good sensitivity, with low limits of detection and quantification. The percentage recovery was found to be 99.13–100.2% for lacosamide and 97.46–101.25% for cobalamin, within acceptable limits. Assay results were 100.01% and 100.22% for lacosamide and cobalamin respectively, indicating accuracy. Precision was confirmed by %RSD values below 2%. Robustness was demonstrated by minor changes in NaOH concentration and detection wavelengths. The method showed no interference from excipients and is suitable for routine quality control. Thus, the developed method is a reliable alternative for the simultaneous analysis of lacosamide and cobalamin in combined pharmaceutical formulations.