MICROENCAPSULATION OF BERGAMOT ESSENTIAL OIL IN ALGINATE-CHITOSAN CAPSULES: CHARACTERIZATION AND STUDY IN SIMULATED GASTROINTESTINAL CONDITIONS

Encapsulation is a technique of enclosing substances into a polymeric wall, allowing the conservation of the intrinsic characteristics of the entrapped material. Smart capsules promote the active release upon specific stimuli, such as pH changes and temperature. For essential oils (EO), encapsulation proved to be efficient for their preservation and protection, since EO have several restrictions for commercial application such as high volatility, rapid oxidation and degradation on exposure to sunlight or UV radiation, besides not being water soluble. In this work, alginate and chitosan were used as wall materials for the encapsulation of bergamot EO. Capsules were prepared by ionic gelation and complex coacervation using alginate 2% (m/V), chitosan 0.2% (m/V) and iron III as crosslinking agent1. The encapsulation efficiency (EE) was 73%. The capsules were investigated in simulated gastrointestinal conditions: PBS buffer (pH 6.8) for 4h and hydrochloric acid with sodium chloride (pH 2)2 for 2h. After the stability test, the capsules maintained their shape. Also, the EO release was 86% and 97% in PBS and acid medium, respectively. These results demonstrate the faster release in acidic medium than in PBS. Thus, the obtained capsules are promising drug delivery systems for gastrointestinal tract, with a faster release in stomach.