Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Polyvinyl alcohol (PVA) was used to reinforce oxidized hydroxypropyl starch to create a plant-based capsule. This capsule exhibits relatively strong mechanical properties and rapid disintegration (< 20 min), meeting the national pharmacopeia standards for loss on drying, disintegration rate, and brittleness. It also remains stable during storage. This study aims to provide insights into improving the brittleness of plant-based capsules.

ABSTRACT
To address the fragility issue of plant-based capsules, this study employed polyvinyl alcohol (PVA) to reinforce the oxidized hydroxypropyl starch (OHPS) matrix, which thereby improved its mechanical properties. An elastic-dominant response was observed for the composite gel system. The addition of PVA reinforced the composite film and contributed to its mechanical strength. Compared with the OHPS film, when the addition amount of PVA was 4%, the tensile strength increased by 27.83% and the elongation at break increased by 64.38%. As the amount of PVA added increased, the swelling ability, solubility, and water vapor transmission rate (WVTR) each decreased to varying degrees, whereas the contact angle gradually rose. The prepared capsules all disintegrated completely within 20 min. When the PVA content was 4%, the loss on drying (10.50%) and the friability of the capsules (less than 5 capsules) both met the requirements of the Chinese Pharmacopeia. Furthermore, after short-term storage of 45 days, the capsules showed no signs of deterioration. No significant differences were observed in the overall characterization, indicating that the homogeneity of each group was good. Meanwhile, scanning electron microscopy images showed that the components were well compatible.