Nanocellulose incorporated oleogel matrix for controlled-release of active ingredients in the lower gastrointestinal tract

Controlled release is often preferred for orally administrated bioactive compounds and drugs. In this study, a nanocellulose (NC) incorporated oleogel encapsulation system was developed for controlled release of active agents. 5-Aminosalicylic acid (5-ASA), an anti-inflammatory drug to treat inflammatory bowel diseases, was used as an example core ingredient for demonstrating the efficacy of the system. Oleogels with/without NC incorporation encapsulating 5-ASA were prepared and tested by in vitro digestion study, and 5-ASA released from the matrix was quantified by a novel UV–Vis spectrometric method developed in this study. The oleogel encapsulation system was characterized by assessing the encapsulation efficiency, oxidative stability, gel hardness, microstructure, and thermal stability. Results showed that sorbitan tristearate-induced oleogel system successfully protected 5-ASA during GI digestion. The incorporation of NC solutions with different NC types, concentrations and volumes further modified the release rate. Specifically, the release of 5-ASA in NC incorporated matrix was <6 % in the gastric phase, and ranged between 17.42 % - 38.28 % in the small intestine depending on the added NC type and concentration. Additionally, the incorporation of NC improved physicochemical stability of the gel matrix. The new 5-ASA quantification method developed in this study is simpler and faster compared with currently available methods.