Streubel A, Siepmann J, Bodmeier R
College of Pharmacy, Freie Universität Berlin, Kelchstr. 31, 12169 Berlin, Germany.
Eur J Pharm Sci. 2003 Jan;18(1):37-45. doi: 10.1016/s0928-0987(02)00223-3.
The aim of this study was to develop and physicochemically characterize single unit, floating controlled drug delivery systems consisting of (i). polypropylene foam powder, (ii). matrix-forming polymer(s), (iii). drug, and (iv). filler (optional). The highly porous foam powder provided low density and, thus, excellent in vitro floating behavior of the tablets. All foam powder-containing tablets remained floating for at least 8 h in 0.1 N HCl at 37 degrees C. Different types of matrix-forming polymers were studied: hydroxypropyl methylcellulose (HPMC), polyacrylates, sodium alginate, corn starch, carrageenan, gum guar and gum arabic. The tablets eroded upon contact with the release medium, and the relative importance of drug diffusion, polymer swelling and tablet erosion for the resulting release patterns varied significantly with the type of matrix former. The release rate could effectively be modified by varying the "matrix-forming polymer/foam powder" ratio, the initial drug loading, the tablet geometry (radius and height), the type of matrix-forming polymer, the use of polymer blends and the addition of water-soluble or water-insoluble fillers (such as lactose or microcrystalline cellulose). The floating behavior of the low density drug delivery systems could successfully be combined with accurate control of the drug release patterns.
(i)聚丙烯泡沫粉末,(ii)成膜聚合物,(iii)药物,以及(iv)填充剂(可选)。高度多孔的泡沫粉末提供了低密度,因此片剂具有优异的体外漂浮行为。所有含泡沫粉末的片剂在37℃的0.1N盐酸中至少漂浮8小时。研究了不同类型的成膜聚合物:羟丙基甲基纤维素(HPMC)、聚丙烯酸盐、海藻酸钠、玉米淀粉、角叉菜胶、瓜尔胶和阿拉伯胶。片剂与释放介质接触后会发生侵蚀,药物扩散、聚合物溶胀和片剂侵蚀对最终释放模式的相对重要性会因成膜剂类型的不同而有显著差异。通过改变“成膜聚合物/泡沫粉末”比例、初始药物载量、片剂几何形状(半径和高度)、成膜聚合物类型、聚合物共混物的使用以及添加水溶性或水不溶性填充剂(如乳糖或微晶纤维素),可以有效地改变释放速率。低密度给药系统的漂浮行为可以成功地与药物释放模式的精确控制相结合。