Modified release microcapsules loaded with red propolis extract obtained by spray-dryer technique: Phytochemical, thermal and physicochemical characterizations

Biopolymers are currently one of the most interesting materials applied in the medical and pharmaceutical fields. The objective of this work was to develop the modified release microcapsules loaded with red propolis extract (RPE) using a spray-dryer technique. In addition, this manuscript characterizes this red propolis microcapsules using phytochemicals, thermal, physicochemical and dissolution test. The RPE was incorporated in the biopolymer solution, and then submitted to spray-dryer technique to obtain modified release microcapsules loaded with RPE; then, they were submitted to different physicochemical characterization technique through SEM analysis, FTIR, thermal analysis (TG and DSC), dissolution test and phytochemical assays. The red propolis microcapsules presented spherical morphology with particle size between 2.5 and 35 μm, when analyzed by SEM technique. The thermal analysis showed that the coating material decreases the thermo-oxidative degradation of the RPE in the microcapsules and according to the calorimetric curves (DSC) and infrared spectra the microencapsulation of the red propolis extract was obtained. The quantification of the bioactive compounds showed high amounts of total phenols (98.3%) and total flavonoids (92.9%) contents, and it was possible determinate the encapsulation degree in microcapsules. The red propolis microcapsules present high antioxidant capacity (90.6%) in sequestering the free radical DPPH˙. The dissolution tests demonstrate slow flavonoids release (between 70 and 100%) from the microcapsules and have proven to be modified release microcapsules during 12 h experiments. The red propolis microcapsules can be applied in pharmaceutical and nutraceutical areas due to modified release property, antioxidant and antibacterial activities.