Zia H, Falamarzian M, Raisi A, Montaseri H, Needham T E
School of Pharmacy, University of Isfahan.
J Microencapsul. 1991 Jan-Mar;8(1):21-8. doi: 10.3109/02652049109021854.
Ethyl cellulose encapsulated aspirin particles, suitable for preparation of direct compression tablets were prepared by the solvent evaporation method. Ethyl acetate was used as a solvent for the polymer in combination with a saturated solution of aspirin as the dispersing medium to prevent partitioning and drug loss. This resulted in a high yield of free-flowing, non-aggregated particles. In vitro-in vivo evaluations of the experimental aspirin tablets (made by direct compression of ethyl cellulose encapsulated particles) and three different commercial aspirin products (a conventional tablet, a timed-release tablet, and a timed-release caplet) were undertaken. Comparison of the dissolution in acidic media at pH 1.2 showed different release profiles for these products. While the conventional tablet and the timed-release caplet showed the highest and the lowest rate of release, respectively; the timed-release tablet and the experimentally made tablet revealed an intermediate rate and very similar release profiles. The cumulative urinary excretion data collected in a complete crossover study, using five healthy subjects further indicated that the experimental tablet has an in vivo availability identical to that of the timed-release tablet.
采用溶剂蒸发法制备了适用于直接压片的乙基纤维素包封阿司匹林颗粒。将乙酸乙酯用作聚合物的溶剂，并与阿司匹林饱和溶液作为分散介质相结合，以防止药物分配和损失。这使得能够高产率地制备出自由流动、不聚集的颗粒。对实验性阿司匹林片剂（由乙基纤维素包封颗粒直接压片制成）和三种不同的市售阿司匹林产品（普通片剂、缓释片剂和缓释胶囊）进行了体外-体内评价。在pH 1.2的酸性介质中进行的溶出度比较显示，这些产品具有不同的释放曲线。普通片剂和缓释胶囊分别显示出最高和最低的释放速率；缓释片剂和实验制备的片剂显示出中等速率且释放曲线非常相似。在一项完整的交叉研究中，使用五名健康受试者收集的累积尿排泄数据进一步表明，实验片剂的体内可用性与缓释片剂相同。
