Ortoton® Recordati Tablets to Generic Methocarbamol (Methoflex) Tablets Switch: In Vitro Comparative Dissolution Assessment, Bioequivalence, Safety, and Tolerability of Methocarbamol Tablets 750 mg in Healthy Volunteers

Purpose: To evaluate the pharmaceutical quality, bioequivalence, safety, and tolerability of investigational methocarbamol 750 mg tablets (Methoflex) in comparison with the reference product (Ortoton® Recordati 750 mg). Methods: In vitro dissolution of test and reference products was assessed using Apparatus II (paddle) in four media (purified water, pH 1.2, 4.5, and 6.8), and similarity (f2) factors were calculated. An open-label, randomized, two-treatment, two-period, crossover bioequivalence study was conducted in healthy adult volunteers under fasting conditions. Pharmacokinetic parameters (Cmax, Tmax, AUC0–t) were determined using a non-compartmental model (Phoenix WinNonlin 8.5), and statistical analysis was performed using SAS 9.4. Safety was evaluated by monitoring adverse events post-dose. Results: Both formulations met USP and BP quality standards, showing rapid dissolution (>85% within 30 minutes) across all media. The test product demonstrated comparable dissolution profiles (f2 similarity) to the reference. Pharmacokinetic parameters (Cmax, Tmax, AUC0–t) were comparable between products. The geometric mean ratios (test/reference) for AUC0–t and Cmax were 103.48 and 110.27, respectively, with 90% confidence intervals within the accepted bioequivalence range (80.00–125.00). No serious adverse events were observed, indicating good tolerability. Conclusion: Methoflex 750 mg tablets are bioequivalent to Ortoton® Recordati 750 mg, with comparable quality, pharmacokinetics, and safety profiles, supporting their use as a therapeutic alternative.