为寻求传统明胶软胶囊囊皮替代物，本研究以羟丙基淀粉（HPS）和琼脂（AG）为原料，甘油（G）为增塑剂，采用流延法成功制备了不同甘油含量的复配软胶囊囊皮；并探究甘油浓度对复配囊皮性能的影响，阐明其作用机理。红外结果表明，复配囊皮中HPS与AG之间存在氢键相互作用；热重结果表明甘油的添加使得HPS与AG相容性降低，随着甘油质量分数升高（0~20%，m/m），复配囊皮热稳定性提高；复配囊皮在600 nm处的吸光度先增大后减小，甘油含量10%（m/m）（10% G+HPS+AG）复配囊皮吸光度最大（0.60），遮光性好；复配囊皮水接触角（WCA）呈先增大后减小趋势，15% G+HPS+AG复配囊皮WCA最大（86.17°），疏水性好；拉伸测试结果表明，15% G+HPS+AG复配囊皮具备较好的杨氏模量（17.47 MPa），拉伸强度（3.17 MPa）和断裂伸长率（94.17%），满足稳定生产条件；与传统明胶囊皮相比，15% G+HPS+AG复配囊皮在干燥贮存条件下更加柔软，具备良好的储存稳定性，且原料均为非动物源，安全性更好。结果表明，HPS-AG复配体系在软胶囊囊皮领域表现出良好的应用潜力，为淀粉基软胶囊囊皮的工业化生产提供了理论基础。

In order to identify a suitable substitute for traditional gelatin soft capsule shells, a series of composite soft capsule shells with different glycerol concentrations were prepared based on a casting method, using hydroxypropyl starch (HPS) and agar (AG) as raw materials and glycerol (G) as a plasticizer. The effects of glycerol concentration on the properties of the composite capsule shells were investigated. Fourier transform infrared spectroscopic analysis revealed hydrogen bond interactions between HPS and AG in the composite capsule shell, whereas the findings of thermogravimetric analysis indicated that the addition of glycerol reduces the compatibility between HPS and AG, thereby leading to an increase in the thermal stability of the composite capsule shells with an increase in glycerol concentration (0~20%, m/m). Absorbance of the composite material at 600 nm initially increased and subsequently declined with increasing glycerol concentration, with maximum absorbance (0.60) being recorded for composite capsule shells with a 10% (m/m) glycerol concentration (10% G+HPS+AG), thus indicating good opacity. Similarly, the water contact angle (WCA) of the composite capsule shells initially increased with increasing glycerol concentration prior to a subsequent decline, with the highest value (86.17°) being obtained for the 15% G+HPS+AG composite capsule shells, indicating good hydrophobicity. The 15% G+HPS+AG composite capsule shells also had good Young’s modulus (17.47 MPa), tensile strength (3.17 MPa), and elongation at break (94.17%), thereby meeting the requirements for stable production. Compared with the traditional gelatin soft capsule shells, the 15% G+HPS+AG composite shells were softer under dry storage conditions and had good storage stability. Moreover, given that the raw materials are of non-animal origin, this would ensure better safety. Our findings indicate that the HPS-AG composite system has promising application prospects in the field of soft capsule shell production, and will provide a theoretical foundation for the industrial manufacture of starch-based soft capsule shells.

国家自然科学基金项目（32272340）