FORMULATION AND CHARACTERIZATION OF HARD, GELATIN‑LIKE CAPSULES USING A FOUR-POLYMER PLANT-BASED SYSTEM
DOI:
https://doi.org/10.53555/zwx1yn84Keywords:
Plant-based capsules, Corn starch–agar–HPMC composite, Gelation kinetics (G′/G″), Rheology and viscosity modeling, Drying kinetics and mechanical hardness, API uniformity and dissolutionAbstract
This study reports the development and characterization of hard, gelatin-like capsules using a novel four-polymer plant-based system comprising corn starch (CS), agar-agar (AA), sodium alginate (SA), and hydroxypropyl methylcellulose (HPMC), with glycerin as a plasticizer. The polymer blend was optimized to achieve controlled viscosity, predictable gelation, and uniform capsule wall formation. Rheological analysis demonstrated shear-thinning behavior suitable for dip-molding, and oscillatory measurements identified the G′/G″ crossover point, confirming a robust sol–gel transition. Drying kinetics followed a first-order exponential decay, yielding capsules with high mechanical hardness and low moisture content. API incorporation and content uniformity analysis showed RSD below 6%, while dissolution studies indicated controlled, diffusion-driven release consistent with Higuchi and first-order models. Stability modeling using the Arrhenius equation predicted reliable long-term shelf life under ambient conditions. Compared with previously reported single- or dual-polymer systems, the proposed four-polymer capsules demonstrated superior mechanical strength, moisture control, release behavior, and stability, highlighting their potential as a plant-based alternative to gelatin capsules.
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