Production of vitamin B1 microparticles by a spray drying process using different biopolymers as wall materials

The aim of this work was to microencapsulate vitamin B1 by spray-drying using different encapsulating agents (arabic gum, carrageenan, chitosan, maltodextrin, modified chitosan, modified starch, pectin, sodium alginate, and xanthan) and to characterize the microcapsules and study their release. Microcapsules with a 0.25% (w/w) content of vitamin B1 were produced. The product yield results ranged from 17%-52% and the encapsulation efficiency from 66%-100%. Three categories of morphology, regular spherical shape, irregular spherical shape with rough surface, and irregular shape, were identified. Their sizes, determined by laser granulometry, ranged from 0.11-1.32 mu m, in terms of number distribution, and from 3.76-34.43 mu m, in volume distribution. Controlled release studies were performed by spectrophotometric analysis, in deionized water (20 degrees C) and simulated gastric fluid (37 degrees C). Different release behaviours were observed from just 10 seconds (modified starch) up to more than 24 hours (xanthan). Kinetic models such as zero-order, first-order, Higuchi, Korsmeyer-Peppas, and Weibull were applied. The Weibull model showed the best fitting with the experimental data. All release tests were repeated after 4 months and showed good stability over time. A mass loss of vitamin B1 lower than 20% was detected. This study demonstrates the possibility of encapsulating vitamin B1 using different encapsulating agents by a spray-drying technique. Depending on the intended applications, for fast release, adequate results were obtained for maltodextrin, arabic gum, modified chitosan, and sodium alginate, and for slow release, adequate results were only obtained for chitosan and pectin.