Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014 Helsinki, Finland.
Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014 Helsinki, Finland.
Int J Pharm. 2017 Oct 30;532(1):269-280. doi: 10.1016/j.ijpharm.2017.09.002. Epub 2017 Sep 6.
Concentrated 3% and 6.5% anionic nanofibrillar cellulose (ANFC) hydrogels were introduced as matrix reservoirs for controlled delivery applications of small molecules and proteins. A further aim was to study how the freeze-drying and subsequent rehydration of ANFC hydrogel affects the rheological properties and drug release of selected model compounds from the reconstructed hydrogels. It was demonstrated that the 3% and 6.5% ANFC hydrogels can be freeze-dried with suitable excipients into highly porous aerogel structures and redispersed back into the hydrogel form without significant change in the rheological properties. Freeze-drying did not affect the drug release properties from redispersed ANFC hydrogels, indicating that these systems could be stored in the dry form and only redispersed when needed. For large molecules, the diffusion coefficients were significantly smaller when higher ANFC fiber content was used, indicating that the amount of ANFC fibers in the hydrogel can be used to control the release rate. The release of small molecules was controlled with the ANFC fiber content only to a moderate extent. The results indicate that ANFC hydrogel can be used for controlled delivery of several types of molecules and that the hydrogel can be successfully freeze-dried and redispersed.
浓度为 3%和 6.5%的阴离子纳米原纤纤维素（ANFC）水凝胶被引入作为小分子和蛋白质的控制释放应用的基质储库。进一步的目的是研究 ANFC 水凝胶的冷冻干燥和随后的再水合如何影响从重建水凝胶中选择的模型化合物的流变性能和药物释放。结果表明，3%和 6.5%的 ANFC 水凝胶可以与合适的赋形剂一起冷冻干燥成具有高多孔气凝胶结构的物质，并且在流变性能没有显著变化的情况下重新分散回水凝胶形式。冷冻干燥不会影响重新分散的 ANFC 水凝胶的药物释放特性，这表明这些系统可以以干燥形式储存，并且仅在需要时再分散。对于大分子，当使用更高的 ANFC 纤维含量时，扩散系数显著减小，这表明水凝胶中 ANFC 纤维的量可用于控制释放速率。小分子的释放仅通过 ANFC 纤维含量进行适度控制。结果表明，ANFC 水凝胶可用于几种类型的分子的控制释放，并且水凝胶可以成功地冷冻干燥和再分散。
