Effects of Hydroxypropyl Methylcellulose on the Properties of Oxidized Hydroxypropyl Starch‐Based Films for Drug Delivery Vehicles

ABSTRACT

To address challenges in enhancing the mechanical strength, moisture barrier properties, and processability of starch‐based materials, oxidized hydroxypropyl starch (OHPS) was adopted as the main raw material, and to improve the mechanical performance of films, hydroxypropyl methylcellulose (HPMC) was incorporated. The results indicated that a progressive increase in HPMC content led to a rise in the viscosity of the gel solution from 738 to 1338.1 mPa·s, indicating the formation of a gel network. Additionally, the composite films exhibited an increase in tensile strength, rising from 22.91 to 27.38 MPa, which shows a maximal enhancement of 19.5%; and the water vapor transmission rate was reduced from 102 to 94 g/m ² ·24 h, representing a 7.6% improvement in moisture barrier properties. At an HPMC addition level of 2.0%, capsule friability was 4 capsules, and the disintegration time in simulated gastric fluid was 14.23 min. All performance indicators met the requirements specified in the Chinese Pharmacopoeia (2020). These findings establish a feasible material foundation and process reference for the development of starch‐based films and capsules derived from OHPS.