A sustained-release pharmaceutical preparation comprising an admixture of uncoated and/or single walled water soluble drug, such as aspirin, and dual walled coated drug. The dual wall structure has an inner wall microencapsular control coating, such as ethyl cellulose, and an outer wall enteric coating such as cellulose acetate phthalate. The dual walled coated drug has a delayed, gradual, long-term release which takes place in the intestines while the uncoated and/or single walled drug has immediate therapeutic properties upon dissolution in the stomach. The outer wall enteric coating may be applied to microencapsulated core drug by a coacervation, spray coating or other process.  
                            一种缓释药物制剂,包括无包衣和/或单壁
水溶性药物(如
阿司匹林)与双壁包衣药物的混合物。双壁结构具有内壁微囊控制涂层(如
乙基纤维素)和外壁肠溶涂层(如
邻苯二甲酸醋酸纤维素)。双壁包衣药物在肠道中具有延迟、渐进、长期释放的特性,而无包衣和/或单壁药物在胃中溶解后具有即时治疗特性。外壁肠溶包衣可通过共凝固、喷涂或其他工艺应用于微胶囊核心药物。