Formulation of Sustained Release Hydrophilic Matrix Tablets of Tolcapone with the Application of Sedem Diagram: Influence of Tolcapone’s Particle Size on Sustained Release

Hydrophilic matrix tablets are a type of sustained release dosage form characterized by distributing a drug in a matrix that is usually polymeric. Tolcapone is a drug that inhibits the enzyme catechol-O-methyl transferase. In recent years, it has been shown that tolcapone is a potent inhibitor of the amyloid aggregation process of the transthyretin protein, and acts by stabilizing the structure of the protein, reducing the progression of familial amyloid polyneuropathy. The main objective of this study was to obtain a sustained release tablet of tolcapone for oral administration with a preferred dosage regimen of 1 administration every 12 or 24 h and manufactured, preferably, by direct compression. The SeDeM Diagram method has been used for the formulation development of hydrophilic matrix tablets. Given the characteristics of tolcapone, the excipient selected for the formation of the polymeric matrix was a high viscosity hydroxypropylmethylcellulose (Methocel(®) K100M CR). A decrease in the particle size of tolcapone resulted in a slower dissolution release of the formulation when the concentration of the polymer Methocel(®) K100M CR was below 29%. These surprising and novel results have given rise to patent number WO/2018/019997.