Development of Controlled Delivery Functional Systems by Microencapsulation of Different Extracts of Plants: Hypericum perforatum L., Salvia officinalis L. and Syzygium aromaticum

Abstract

Extracts of different plants (Hypericum perforatum L., Salvia officinalais L. and Syzygium aromaticum) were microencapsulated. Different microparticles were prepared by a spray drying process, and they were fully characterized and evaluated in terms of controlled release. The product yield of the spray dryer varied from 26.5 to 65.5 wt%. All the microparticles present a regular shape, a very smooth surface and a mean size smaller than 20 mu m. The total release was achieved in less than 70 min. The encapsulation efficiency was around 100%. The release profiles were simulated and evaluated using different kinetic models: Korsmeyer-Peppas (R-2: 0.795-0.992), Weibull (R-2: 0.973-0.999) and Baker-Lonsdale (R-2: 0.855-0.964). These mathematical models allowed the evaluation of the mass transport mechanisms involved in the release, which, in turn, helps to design a system with specific characteristics. Finally, the Weibull model presents a better adjustment to the experimental release profiles, and the drug transport mechanism involved in almost all the release profiles studied is by an anomalous transport.