Extraction, physicochemical characterization, functionality, and excipient ability of corn fiber gum-starch isolate from corn milling industry waste

Corn processing industries generate an extensive fibrous byproduct consisting of corn fiber gum (CFG) and residual starch (S). The present study hypothesized that CFG and S could be isolated as a single crosslinked conjugate. The isolated CFG-S conjugate was acidic, with a pKa value of 11.49, and a swelling index of 99.60%. Henderson-Hasselbalch equation predicted negligible ionization throughout the gastrointestinal pH range. The DSC thermogram highlights glass transition and temperature-specific structure stabilization through the exothermic crystallization domain. FTIR, SEM & XRD confirmed the structural conjugation and integrity of the conjugate. Tablets containing Venlafaxine hydrochloride as a model drug were prepared using CFG-S (14 and 57%) as excipient by wet granulation method. Percentage cumulative drug release with low concentration was up to 99.67175 +/- 0.09 % in 5 h whereas with high concentration, it was extended to 12 h (P < 0.05). Korsemayer-Peppas release exponent indicates zero order (R2 = 0.9935) kinetics with super case-II anomalous transport showing diffusion and erosion as drug release mechanisms. The results confirmed that CFG-S isolate could act as a good binding agent at low concentrations and release extending cross-linked matrix former at a higher concentration for release retardant excipient.

Automated summary

Corn fiber gum and residual starch can be isolated as a single crosslinked conjugate with acid properties. The isolated conjugate showed integrity and delay release properties. The results suggest that the conjugate can be a potential excipient for sustained release formulations.