Preliminary evaluation and studies on the preparation, characterization and in vitro release studies of different biopolymer microparticles for controlled release of folic acid

Abstract

Folic acid is a synthetic form of folate (vitamin B9) commonly used for food fortification. However, its vulnerability to processing and storage implies loss of efficiency. The objective of this work was to study folic acid controlled delivery systems produced by a spray-drying process. Microparticles of folic acid, using different biopolymers as encapsulating agents, were prepared. These folic acid microparticles were then evaluated for their drug entrapment efficiency and in vitro release profile. The biopolymer used influenced the type of particles obtained and their characteristics. Spherical microcapsules with a regular shape were produced with arabic gum. modified chitosan, pectin and sodium alginate but in the case of the modified starch, more irregular particles were produced. Encapsulation efficiency was around 100%, with the exception of the microparticles prepared with modified starch. Other important conclusion is related with the final purpose of the capsules. If it is necessary a slower release, pectin or sodium alginate should be selected as encapsulating agent; on the other hand, for a more immediate release, particles with modified starch, modified chitosan or arabic gum should be produced. Baker-Lonsdale, Weibull and Korsmeyer-Peppas models governing the controlled release of active compounds were applied and discussed, being the Weibull model the one that best fits to the experimental results. The use of models to predict in vivo bio-performance is an advantage in the development of new products and in the design of new solutions for other microencapsulated systems.