Young Paul M, Edge Stephen, Staniforth John N, Steele D Fraser, Price Robert
Pharmaceutical Technology Research Group, Department of Pharmacy and Pharmacology, University of Bath, Bath, UK.
Pharm Dev Technol. 2007;12(2):211-6. doi: 10.1080/10837450601168763.
The relationship between the apparent moisture content and moisture sorption of modified starches was investigated. Samples of sodium starch glycolate (SSG), pregelatinized starch (PGS) and potato starch (PS) were stored for various times at 44% or 75% relative humidity (RH) to produce samples with moisture contents of up to 14%, as determined by loss on drying (LOD). Evaluation of LOD and mass gain data suggested that measured mass gain equated to predicted LOD values for PGS and PS. However, in SSG there was a nonstoichiometric relationship between mass gain and predicted LOD. In addition, samples of SSG displayed hysteresis during dynamic vapor sorption (DVS) cycling in that an apparent mass loss of about 2-3% was observed for two of the SSGs, with PS and PGS exhibiting reversibility. In some cases, SSG exhibited an apparent mass loss during the DVS cycle at with 50% RH. These observations suggest that one or more of the components of SSG "interact" with moisture. Because X-ray diffraction suggested there was no dramatic change in the crystallinity of SSG, an exchange of residual SSG solvent, alcohol, with moisture may, in part, explain the moisture sorption behavior of SSG.
研究了变性淀粉的表观水分含量与吸湿之间的关系。将羟丙基二淀粉磷酸酯（SSG）、预糊化淀粉（PGS）和马铃薯淀粉（PS）样品在44%或75%相对湿度（RH）下储存不同时间，以制备干燥失重（LOD）测定水分含量高达14%的样品。对LOD和质量增加数据的评估表明，PGS和PS的实测质量增加与预测的LOD值相等。然而，在SSG中，质量增加与预测的LOD之间存在非化学计量关系。此外，SSG样品在动态蒸汽吸附（DVS）循环过程中表现出滞后现象，即两个SSG样品出现约2-3%的表观质量损失，而PS和PGS表现出可逆性。在某些情况下，SSG在50%RH的DVS循环中出现表观质量损失。这些观察结果表明，SSG的一种或多种成分与水分“相互作用”。由于X射线衍射表明SSG的结晶度没有显著变化，SSG残留溶剂乙醇与水分的交换可能部分解释了SSG的吸湿行为。
