Rapid preparation of polysaccharide hydrogel capsule free of organic reagents to control drug release

Polysaccharide-based hydrogels for drug delivery systems have attracted considerable research. The less use of cross-linking agents is beneficial in reducing the side effects on humans. The aim of this study is to prepare a drug delivery vehicle which allows the drug to be less likely or not released in the stomach but is usually released in the intestine. Here, we synthesized hydrogel capsules with cellulose as carrier and sodium alginate (SA) as shell, respectively. The hydrogel capsule break-up process was controlled by varying the concentration of CaCl2 and SA, the weight ratio of sodium carboxymethylcellulose (CMC) and hydroxyethyl cellulose (HEC) and the size of hydrogel capsules. In addition, the hydrogel capsules showed controlled release under simulated gastric acid conditions by continuous gastrointestinal simulations and showed sustained release in simulated intestinal fluid.