Optimizing fabrication of pharmaceutical capsule shell: A factorial design of corncob-MCC/carrageenan/starch biofilm Scientific paper

Abstract

This study develops biodegradable soft-capsule films using carrageenan, tapioca starch, glycerol and microcrystalline cellulose (MCC) derived from corncob waste as a halal- and vegetarian-friendly alternative to gelatin. A 2³ fac­torial design evaluated the effects of carrageenan (15–25 wt. %), MCC (5–15 wt. %) and glycerol (10–20 wt. %) on tensile strength (TS), elongation (EL) and Young’s modulus (YM). The produced biofilms were characterized using mech­anical testing, FTIR, XRD, SEM, TGA, disintegration tests and ANOVA. Mech­anical performance varied widely among samples. Among the synthesized bio­films, sample 2 exhibited the highest TS (6.565 MPa) and YM (97.029 MPa), while sample 5 showed the greatest ductility and the shortest disintegration time, reach­ing approximately 20 % and 12 min, respectively, indicat­ing rapid water-induced matrix breakdown associated with the hygroscopic nature of the polysaccharide-
-based system. Regression models showed R² values of 84.48, 97.17 and 94.18 % for TS, EL and YM, respectively. XRD confirmed an MCC crystal­linity of 62.6 %. The TGA results confirm the films’ thermal stability and show moisture uptake and char residue consistent with those of the other analyses. Overall, the carrageenan–starch–MCC–glycerol system offers tuneable pro­per­ties, although further optimization is required for moisture control and purity.