Use of rotary fluidized-bed technology for development of sustained-release plant extracts pellets: Potential application for feed additive delivery1

Abstract

The aim of this study was to develop sustained release plant extracts as a potential alternative to antibiotic growth promoters for growing pigs. Pellets with a core based on microcrystalline cellulose and 3 active compounds (eugenol, carvacrol, and thymol) were prepared using rotary fluidized-bed technology. Two particle sizes were produced that had a mean size of approximately 250 and 500 mum. Results show the process was able to produce pellets with a spherical and homogenous form when 10% of the active compounds were incorporated into the core. When active compounds were increased to 20%, the pellet became stickier, and the yield decreased from 90 to 65%. Different amounts of coating in the form of an aqueous-based ethylcellulose (EC) dispersion (Surelease) were applied to the core to modify the release of active compounds. The efficacy of the coating was evaluated in vitro using a flow-through cell apparatus. The time to achieve 50 and 90% dissolution increased with the increase in particle size (P < 0.05) and the increase in EC-coating level from 10 to 20% (wt/wt; P < 0.05), indicating the ability of the process to slow release depending on particle size and the amount of polymer applied. Differences in the release of the active compounds were observed in the same formulation of pellets, except for the formulation with small 10%-EC-coated particles, in which the active compounds were rapidly dissolved (more than 85% in 15 min or less). For all other formulations, the dissolution time for eugenol was always faster than for thymol or carvacrol. The close monitoring of plant extract behavior in the gastrointestinal tract could become a key factor in the continued use of phyto-molecules as alternatives to antibiotic growth promoters and in optimizing the balance between cost and efficacy. Different microencapsulation technologies can be used, of which the rotary fluidized bed warrants consideration because of the quality of the products obtained.

Microencapsulated acids associated with essential oils and acid salts for piglets in the nursery phase

“…These results are attributed to changes in the microbial populations of the small and large intestines, favoring the survival of lactic acidproducing bacteria and the reducing the population of pathogenic bacteria (MICHIELS et al, 2009), which changed the VFA pattern ( VAN BEERS-SCHREURS et al, 1998;SURYANARAYANA et al, 2012). These effects were most pronounced when the essential oils and organic acids were microencapsulated, which improved the ability of these acids to reach the large intestine and remain active (MEUNIER et al, 2006). The changes in the AGV levels observed in this study also corroborate those observed by Grilli et al (2010) and Willamil et al (2011), who revealed that microencapsulated organic acids can modify and improve cecal fermentation.…”

“…This finding demonstrates that microencapsulation prevents the absorption and immediate metabolism of duodenal acids (PIVA et al, 2007b) to ensure that sufficient quantities are available at the end of the digestive tract (MEUNIER et al, 2006). …”

“…The resultant microcapsule slowly and continuously releases the active ingredients throughout the digestive tract, increasing their availability to the lumen of the ileum and colon (MEUNIER et al, 2006). The objective of this study was to evaluate the effects of supplementation with a commercial mixture of organic acids and inorganic acids mixed with essential oils on the performance, the control of diarrhea and efficiency parameters and the intestinal health of piglets in the nursery phase.…”

Botanical alternatives to antibiotics for use in organic poultry production

“…Because the cecum is at the posterior end of the gastrointestinal tract, the phytobiotics must retain their activity during transit through the entire gastrointestinal system. Some studies conclude that the antimicrobial property is either reduced or eliminated while moving through the gastrointestinal tract (Kohlert et al, 2002;Meunier et al, 2006). Given the location of Salmonella and Campylobacter, retention of the antimicrobial is essential for efficacy (Arsi et al, 2014).…”

Impact of bioactive substances on the gastrointestinal tract and performance of weaned piglets: a review

“…Protection of essential oils, e.g. by micro-encapsulation, may be a valuable strategy in animal feeding (Meunier et al, 2006 and2007), and more studies are clearly required in this area.…”