| 摘要 |
Orally administrable tablets for controlled release of 4-aminosalicylic acid (I) comprise (I) in a hydrophilic matrix with an enteric coating. Also claimed is a process for producing the tablets. The hydrophilic matrix comprises a cellulose deriv., esp. hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose (HPMC), methylcellulose or carboxymethyl cellulose. The enteric coating comprises an acrylic polymer, esp. a copolymer of ethyl acrylate and ethyl methacrylate. The tablets comprise 40-90 (esp. 60-80) wt.% (I), 10-40 (esp. 15-25) wt.% hydrophilic polymer and 0.5-5 (esp. 1-2.5) wt.% enteric coating. The tablets are produced by forming granules contg. (I), hydrophilic polymer(s) and additive(s); compressing the granules to form tablets; and coating the tablets with enteric material. USE/ADVANTAGE - (I) is an antiinflammatory agent useful for treating haemorrhage rectocolitis and Crohn's disease. The tablets release (I) progressively in the intestinal tract, thereby protecting the gastric mucosa from the irritant effects of (I) and protecting (I) from degradation by gastric acid. In an example, the tablets comprise 500 mg (I), 100 mg HPMC K100, 5 mg talc, 8.7 mg Mg stearate and 12.15 mg Aerosil. The coating comprises 8.03 mg 'Eudragit' L100-55 (RTM), 0.75 mg diethylphthalate, 1.77 mg talc and 1.44 mg 'Sedisperse' (RTM).
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