High‐performance aminosilane‐infused alginate capsules for sustained drug release

Abstract

AbstractSodium alginate (AlgNa) is often used to prepare oral drug capsules, offering the advantages of facile carrier formation and pH sensitivity. However, these capsules suffer from high porosity, large pore size, and mechanical and physiological instabilities. Although the performance of AlgNa in oral drug carriers can be enhanced through hybridization with other substances, this results in increased complexity and additional preparation steps. To address this problem, organic–inorganic hybrid capsules are herein prepared via the one‐step incorporation of aminosilanes (3‐aminopropyltriethoxysilane and 3‐(2‐aminoethylamino)propyltrimethoxysilane) into AlgNa and evaluated as delivery vehicles for the sustained release of a model drug, diclofenac sodium. The hybrid capsules show elevated drug encapsulation efficiencies (up to 92.7%) and pH responsiveness and outperform pure alginate capsules, exhibiting contraction and low release rates (<10%) in a simulated stomach environment (pH 1.2) and swelling and sustained release (10 h) in a simulated intestinal environment (pH 7.4). The formation of siloxane bonds between the aminosilane molecules results in stronger and more compact capsule membranes contributing to sustained drug release. Thus, our results demonstrate the potential of the proposed capsules, fabricated using a simple ecofriendly method, as carriers for sustained drug release.