Formulation, Design and Optimization of Taste Masked Effervescent Tablet Containing Methocarbamol

Methocarbamol is a skeletal muscle relaxant drug. In this study, we investigated the potential of developing methocarbamol effervescent tablets to facilitate drug administration. Effervescent tablets containing 1000 mg methocarbamol were prepared using direct compression method. The effect of various formulations parameters such as citric acid, sodium bi-carbonate, PEG 6000, PVP k30 on different physicochemical properties of tablets were evaluated at two levels. Different formulations with various amounts of mentioned excipients along with constant amount of methocarbamol, sucralose, mannitol and different flavoring agents were prepared and their properties including hardness, friability, pH, effervescent time, CO2 content and taste were studied. Optimized formulation was B8 which contained 400 mg of citric acid, 525 mg of sodium bicarbonate, 226.5 mg of PVP k30, 113.2 mg of PEG 6000, 100 mg of mannitol and 30 mg of sucralose. This formulation had effervescent time of 112.67± 2.05 seconds, hardness of 71.10± 2.51 N and pH of 6.01±0.02. Statistical analysis by Design Expert software showed that the hardness of tablets is mostly affected by the amount of PEG 6000. Volunteers reported that sour cherry had the most pleasant taste to them. In summary, current effervescent tablets are shown to be suitable vehicles for methocarbamol with potential for use in patients with swallowing problems and will enhance patience compliance.