Pongjanyakul Thaned, Priprem Aroonsri, Puttipipatkhachorn Satit
Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
J Control Release. 2005 Oct 3;107(2):343-56. doi: 10.1016/j.jconrel.2005.07.003.
Physicochemical properties of sodium alginate-magnesium aluminum silicate (SA-MAS) composite films were investigated and a potential as a film former of SA-MAS dispersion for modifying drug release from tablets was evaluated as well. Interaction between SA and MAS in the composite films was revealed using FTIR spectroscopy. Thermal behavior of the composite films was changed due to the complexation of SA and MAS. Powder X-ray diffractometry data suggested that a higher crystallinity of the composite film and a phase-separated microcomposite were formed. The composite films in the ratios of 1:0.5 and 1:1 showed the increases of tensile strength and percentage of elongation when compared with SA films. Water vapor permeability of the composite films tended to increase with increasing ratio of MAS. The decreases in water uptake and drug permeability in 0.1 M HCl were found in the composite films. A positive charge drug, propranolol HCl, provided a higher affinity on the composite films than a weakly acidic nonelectrolyte, acetaminophen, resulting in a longer lag time and a higher partition coefficient depending on the content of MAS in the composite films. This was due to the complex formation of propranolol HCl and MAS. Using SEM, the tablets coated with SA-MAS dispersion had a smooth surface, while those with SA dispersion showed a pinholing on the surface, resulting in a faster drug release. The drug release profiles of the tablets could be modified by coating with the composite film at different coating levels. This finding suggests that MAS could improve physicochemical properties of the SA films, leading to a novel coating material of the SA-MAS dispersion for modifying drug release from tablets.
研究了海藻酸钠-硅酸镁铝（SA-MAS）复合膜的物理化学性质，并评估了SA-MAS分散体作为成膜剂用于改变片剂药物释放的潜力。利用傅里叶变换红外光谱（FTIR）揭示了复合膜中SA和MAS之间的相互作用。由于SA和MAS的络合作用，复合膜的热行为发生了变化。粉末X射线衍射数据表明，复合膜形成了更高的结晶度和相分离的微复合材料。与SA膜相比，1:0.5和1:1比例的复合膜的拉伸强度和伸长率有所增加。复合膜的水蒸气透过率随着MAS比例的增加而趋于上升。在复合膜中发现其在0.1 M HCl中的吸水率和药物渗透率降低。带正电荷的药物盐酸普萘洛尔对复合膜的亲和力高于弱酸性非电解质对乙酰氨基酚，根据复合膜中MAS的含量，导致更长的滞后时间和更高的分配系数。这是由于盐酸普萘洛尔和MAS形成了络合物。使用扫描电子显微镜（SEM）观察到，用SA-MAS分散体包衣的片剂表面光滑，而用SA分散体包衣的片剂表面有针孔，导致药物释放更快。通过在不同包衣水平下用复合膜包衣可以改变片剂的药物释放曲线。这一发现表明，MAS可以改善SA膜的物理化学性质，从而形成一种用于改变片剂药物释放的新型SA-MAS分散体包衣材料。
