Influence of Different Levels of Acetylation on Retrograded Corn Starch Polymer in Colon‐Targeted Budesonide Tablets

ABSTRACT The current study examined the impact of varying degrees of acetylation on dual‐modified (retrograded and acetylated) corn starch as a polymer in formulating colon‐targeted tablets, with a focus on drug release and suitability for direct compression, using budesonide as a model drug. Starch acetylation was achieved using acetic anhydride as the acetylating agent and water/acetic acid as the solvent, preparing starch with low, medium, and high degrees of substitution (DS). It was evident that starch with a high degree of acetylation provided the most promising characteristics as an excipient for colon‐targeted drug delivery. Specifically, the tablet formulation with a high DS of 2.01 ± 0.03 (F4) demonstrated optimal mechanical strength, hardness, and favorable physical properties for controlled drug release in the colon. Dissolution studies showed that F4 released 15.24% of the drug in pH 1.2 within 2 h, followed by 22.34% and 59.04% in pH 7.4 and pH 6.8 phosphate buffers, covering the ileo‐colonic region. In conclusion, the study highlighted the importance of the DS in the acetylation of dual‐modified starch for colon‐targeted tablet formulations, underlining its potential as an ideal option for drug delivery applications by achieving controlled drug release in the targeted ileo‐colonic region.