Bando Hiroto, McGinity James W
Drug Dynamics Institute, College of Pharmacy, University of Texas at Austin, 78712, USA.
Int J Pharm. 2006 Apr 26;313(1-2):43-8. doi: 10.1016/j.ijpharm.2006.01.021. Epub 2006 Feb 17.
Cast films composed of mixtures of Eudragit S100:L100 (1:1) and plasticized with triethyl citrate (TEC) were prepared from aqueous dispersions and organic solutions, and the physicochemical properties and the weight loss of cast films during dissolution testing were examined. The tensile strength of the organic cast films was significantly higher and the percent elongation was lower than that of the aqueous cast films. The weight loss of the organic films was also lower than that of the aqueous films. Furthermore, leaching of the TEC from the aqueous films was rapid and the TEC was found to diffuse from the films within one hour at pH 6.0, the pH at which the Eudragit S100:L100 (1:1) films were insoluble. In contrast to the aqueous films, minimal levels of the TEC diffused from the organic cast films, and the disintegration of acrylic polymers occurred simultaneously with the release of TEC from the film during dissolution testing at pH 7.0. For Eudragit L100-55, which could form films at lower TEC levels than Eudragit S100:L100, both the organic and aqueous films showed the same weight loss after four hours in pH 5.0 media. These results demonstrated that for Eudragit S100:L100 cast films, the high levels of TEC needed for film formation from aqueous dispersions resulted in rapid dissolution and disintegration at pH 6.0 and above. While aqueous dispersions are preferred for the coating of solid substrates, for Eudragit S100:L100 film coatings, a change from organic solutions to aqueous dispersions in the coating process will impact film properties and product performance.
由Eudragit S100与L100（1:1）的混合物组成并以柠檬酸三乙酯（TEC）增塑的流延膜，分别由水分散体和有机溶液制备而成，并对其理化性质以及溶解测试过程中流延膜的失重情况进行了考察。有机流延膜的拉伸强度显著更高，而伸长率则低于水性流延膜。有机膜的失重也低于水性膜。此外，TEC从水性膜中的浸出速度很快，并且发现在pH 6.0（Eudragit S100:L100（1:1）膜在此pH下不溶）时，TEC在一小时内从膜中扩散出来。与水性膜相反，从有机流延膜中扩散出的TEC含量极低，并且在pH 7.0的溶解测试过程中，丙烯酸聚合物的崩解与TEC从膜中的释放同时发生。对于Eudragit L100-55，其能在比Eudragit S100:L100更低的TEC水平下成膜，在pH 5.0介质中放置4小时后，有机膜和水性膜的失重情况相同。这些结果表明，对于Eudragit S100:L100流延膜，从水分散体制备成膜所需的高含量TEC导致在pH 6.0及以上时快速溶解和崩解。虽然水分散体更适合用于固体基质的包衣，但对于Eudragit S100:L100薄膜包衣，在包衣过程中从有机溶液转变为水分散体将影响膜的性质和产品性能。
