| Encapsulation is the process by which tiny particles or droplets are surrounded by a coating material or embedded in a homogenous or heterogeneous matrix to protect many useful properties of molecules entrapped.;In this study Piroxicam (an NSAID which is a non-selective COX inhibitor possessing both analgesic and antipyretic properties) and vegetable canola oil were encapsulated into multilayer biopolymer matrices consisting of three types of maltodextrins and beta Cyclodextrin, whey protein, lambda carrageenan and surfactants. The emulsions were freeze-dried for 72 hours and the collected nano-particles were studied for water activities and encapsulation efficiencies. The stability of systems was evaluated by monitoring phase separation in emulsion systems. The sizes of the particles were measured using atomic force microscopy and Flowcam technology and factors that retain to the controlled release of the encapsulated substances were investigated. After 60 days of storage of the samples at 4°C, no phase separation was observed while control emulsion with no dextrin underwent phase separation after 72.hours. AFM and Flowcam images indicated that the particles were spherical, with sizes between 2 and 6 microm. A temperature of 60°C and a water activity value as low as 0.537 were found to be favorable for partial release of oil and Piroxicam respectively. Encapsulation efficiencies of all the dextrin particles ranged from 70.37% - 83.73%. Water sorption data was fitted into GAB and BET isotherm models. This study indicated that dextrins are excellent emulsion stabilizers and ideal carbohydrate matrices for encapsulation and controlled release of lipophilic substances. |
