Preparation of Insoluble Matrix Tablets of Theacrine

Background Theacrine (1,3,7,9-tetramethyluric acid, TC) is a purine alkaloid rich in the tender leaves of an unusual Chinese tea known as Kucha. TC possessed diverse pharmacological activity including antioxidative, anti-inflammatory, analgesic and anti-depressive effects. Aim In this work, sustained release tablets of TC were intended to be developed with insoluble matrix material to provide a kind of preparation of prolonged action. Methods Direct tableting process and wet granulation tableting process were screened for preparing insoluble matrix tablets of TC. Single factor testes were carried out for the formulation optimization by using drug release behaviour as evaluation index. The parameter f 2 was used to assess the similarity of the drug release behaviour of TC tablets prepared by different formulations. The common quality of TC tablets prepared by optimized formulation was investigated as well. Results With ethyl cellulose (EC) as sustained matrix material, lactose as filler, aerosil as lubricant and anhydrous ethanol as moistening agent, the TC insoluble matrix tablets of sustained release were successfully prepared by wet granulation tableting method. The prepared TC tablets showed no obvious burst effect with about 40% released within 2 h, and TC was almost completely released within 12 h with an accumulative drug release percentage of 84.89%. The results of common examination showed that the TC tablets were in line with the requirements of Chinese Pharmacopoeia. Conclusion TC tablets of good sustained release behaviour were prepared simply by wet granulation tableting process with EC as release control materials. This work provided scientific evidence for development of TC preparation of prolonged action.