Ritthidej Garnpimol C, Phaechamud Thawatchai
Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, Thailand.
Drug Dev Ind Pharm. 2003 May;29(5):585-94. doi: 10.1081/ddc-120018647.
Solution of chitosan in dilute acetic acid was prepared to have an apparent viscosity of 125 mPa s and mixed with solution of anionic water-soluble dye. The effects of concentration and type of dye and molecular weight and percentage deacetylation of chitosan on their miscibility and physical stability were investigated. High concentration of dye and high molecular weight and percentage deacetylation of chitosan resulted in precipitation or colloidal dispersion due to ionic interaction between dye and the polymer. The effect was more prominent upon storage. The miscibility of dye and the polymer depended on the molecular configuration and ionic group in the dye molecule. It was ranked brilliant blue approximately euqal to green FS > fast green > ponceau SX approximately euqal to green sunset yellow > erythrosine approximately euqal to green tartrazin > indigo carmine. Solutions of low molecular weight chitosan with and without green FS were then used as coating formulations onto propranolol hydrochloride core tablets. There was no color migration on coated tablets even after storage for 1 year. Disintegration and drug dissolution from tablets coated with colored film were slightly slower than those from tablets coated with plain film and core tablet, respectively. This was corresponding to the results of swelling and dissolution of cast films. However, all tablets conformed to the specification in monograph of USP XXIV.
制备壳聚糖在稀醋酸中的溶液，使其表观粘度为125 mPa·s，并与阴离子水溶性染料溶液混合。研究了染料的浓度和类型、壳聚糖的分子量和脱乙酰度对它们的混溶性和物理稳定性的影响。由于染料与聚合物之间的离子相互作用，高浓度的染料以及壳聚糖的高分子量和高脱乙酰度导致沉淀或胶体分散。储存时这种影响更为显著。染料与聚合物的混溶性取决于染料分子中的分子构型和离子基团。其顺序为亮蓝≈绿色FS＞固绿＞丽春红SX≈日落黄＞赤藓红≈柠檬黄＞靛蓝胭脂红。然后将含有和不含有绿色FS的低分子量壳聚糖溶液用作盐酸普萘洛尔片芯的包衣制剂。即使储存1年后，包衣片上也没有颜色迁移。有色薄膜包衣片的崩解和药物溶出分别比素片包衣片和片芯稍慢。这与流延膜的溶胀和溶解结果一致。然而，所有片剂均符合美国药典XXIV专论中的规格。
