Department of Physical Chemistry and Biophysics, Faculty of Pharmacy, Wroclaw Medical University, ul. Borowska 211A, 55-556 Wroclaw, Poland.
Molecules. 2020 Dec 3;25(23):5711. doi: 10.3390/molecules25235711.
Targeted drug delivery systems are a very convenient method of treating inflammatory bowel disease. The properties of pectin make this biopolymer a suitable drug carrier. These properties allow pectin to overcome the diverse environment of the digestive tract and deliver the drug to the large intestine. This investigation proposed bipolymeric formulations consisting of the natural polymer pectin and a synthetic polymer containing the drug 5-aminosalicylic acid. Pectin beads were prepared via ionotropic gelation involving the interaction between the hydrophilic gel and calcium ions. The obtained formulations consisted of natural polymer, 5-aminosalicylic acid (5-ASA) and one of the synthetic polymers, such as polyacrylic acid, polyvinylpyrrolidone, polyethylene glycol or aristoflex. The release of the drug was carried out employing a basket apparatus (USP 1). The acceptor fluid was pH = 7.4 buffer with added enzyme pectinase to reflect the colon environment. The amount of the released drug was determined using UV-Vis spectrophotometry at a wavelength of λ = 330 nm. The kinetics of the drug dissolution revealed that none of the employed models was appropriate to describe the release process. A kinetic analysis of the release profile during two release stages was carried out. The fastest drug release occurred during the first stage from a formulation containing pectin and polyethylene glycol. However, according to the applied kinetic models, the dissolution of 5-ASA was rather high in the formulation without the synthetic polymer during the second stage. Depending on the formulation, 68-77% of 5-ASA was released in an 8-hour time period. The FTIR and DSC results showed that there was no interaction between the drug and the polymers, but interactions between pectin and synthetic polymers were found.
靶向药物递送系统是治疗炎症性肠病的一种非常方便的方法。果胶的特性使其成为一种合适的药物载体。这些特性使果胶能够克服消化道的多样化环境，并将药物递送到大肠。本研究提出了由天然聚合物果胶和含有药物 5-氨基水杨酸的合成聚合物组成的两亲性制剂。通过涉及亲水性凝胶与钙离子相互作用的离子凝胶化制备果胶珠。所得制剂由天然聚合物、5-氨基水杨酸（5-ASA）和一种合成聚合物组成，如聚丙烯酸、聚乙烯吡咯烷酮、聚乙二醇或 aristoflex。采用篮法（USP 1）进行药物释放。接受流体为 pH = 7.4 缓冲液，加入果胶酶以反映结肠环境。使用 UV-Vis 分光光度法在 λ = 330nm 处测定释放药物的量。药物溶解动力学表明，所采用的模型均不适用于描述释放过程。对两个释放阶段的释放曲线进行了动力学分析。含有果胶和聚乙二醇的制剂在第一阶段的药物释放最快。然而，根据应用的动力学模型，在第二阶段，不含合成聚合物的制剂中 5-ASA 的溶解度相当高。根据制剂的不同，5-ASA 在 8 小时内释放了 68-77%。FTIR 和 DSC 结果表明，药物与聚合物之间没有相互作用，但发现果胶与合成聚合物之间存在相互作用。
