Nunthanid Jurairat, Wanchana Suchada, Sriamornsak Pornsak, Limmatavapirat Sontaya, Luangtana-anan Manee, Puttipipatkhachorn Satit
Faculty of Pharmacy, Silpakorn University, Nakhon Pathom 73000, Thailand.
Drug Dev Ind Pharm. 2002 Sep;28(8):919-30. doi: 10.1081/ddc-120006424.
The effect of heat on the characteristics of chitosan film coated on theophylline tablets was studied. Chitosan of high viscosity grade with molecular weight in the range of 800,000-1,000,000, 80-85% degree of deacetylation was used as a film former by dissolving in 1% v/v acetic acid solution. The coated tablets had been cured at 40, 60, and 100 degrees C for 6, 12, and 24 hr. The morphology of the film at the edge and surface of coated tablets was investigated using scanning electron microscopy. Film cracking was increased and clearly observed in the coated tablets cured at 100 degrees C for 24 hr. As a result, more water could be absorbed into the tablets, followed by faster disintegration and faster drug release. The evidence of partial conversion of chitosonium acetate to chitin in the 13C nuclear magnetic resonance (NMR) spectra of chitosan films cured at 40, 60, and 100 degrees C was observed, but it had no effect on drug release behavior. Theophylline tablets coated with chitosan films gave sustained release behavior in various media, i.e., distilled water, 0.1 N hydrochloric acid, pH 4.5 acetate buffer, and pH 6.8 phosphate buffer. In addition, the film coating temperature at 55-60 degrees C and curing process at 40 and 60 degrees C had no effect on the drug release from theophylline tablets coated with chitosan polymer. Finally, it might be concluded that both the physical and chemical properties of chitosan films were affected by heat.
研究了热对茶碱片包衣壳聚糖膜特性的影响。使用分子量在800,000 - 1,000,000范围内、脱乙酰度为80 - 85%的高粘度级壳聚糖，通过溶解于1% v/v乙酸溶液中作为成膜剂。包衣片在40、60和100℃下分别固化6、12和24小时。使用扫描电子显微镜研究包衣片边缘和表面的膜形态。在100℃下固化24小时的包衣片中，膜破裂增加且清晰可见。结果，更多的水可被片剂吸收，随后崩解更快且药物释放更快。在40、60和100℃固化的壳聚糖膜的13C核磁共振（NMR）光谱中观察到乙酸壳聚糖部分转化为几丁质的证据，但这对药物释放行为没有影响。壳聚糖膜包衣的茶碱片在各种介质中，即蒸馏水、0.1 N盐酸、pH 4.5乙酸盐缓冲液和pH 6.8磷酸盐缓冲液中呈现缓释行为。此外，55 - 60℃的包衣温度以及40和60℃的固化过程对壳聚糖聚合物包衣的茶碱片的药物释放没有影响。最后，可以得出结论，壳聚糖膜的物理和化学性质均受热影响。
