Modulating drug release from poly(lactic‐co‐glycolic) acid microparticles by the addition of alginate and pectin

Abstract

The aim of the present work is the characterization of PLGA microparticles including biopolymers for the controlled release of tilmicosin, a broad‐spectrum antibiotic. Microparticles were prepared using the double‐emulsion solvent evaporation technique. The effect of alginate and pectin incorporation over particle size and porosity, encapsulation efficiency (EE) and pH‐responsive drug release was evaluated. Formulations presented a mean particle size of 5.5 μm approximately and a drug EE ranged from 22%–57%. PLGA‐Alginate particles showed an increased porosity. Tilmicosin release profiles from PLGA and PLGA‐biopolymer microparticles were affected by the particular combination of polymers and the pH of the release medium. The experimental data was simulated using a mathematical model, which takes into account the autocatalytic polymer degradation and the different mechanisms of drug transport. The combination of PLGA and biopolymers strongly influenced the morphology of the particles, offering the possibility of controlling the drug release profiles according to the therapy.

Influence of composition on the internal diffusion mechanism of pectin–starch gel beads

“…Similar values were found for polylactic‐co‐glycolic particles added of pectin and alginate. EE of tilmicosin ranged from 22% to 57% and release rate showed agreement with the increased matrix porosity and swelling behavior of biopolymers 25 …”

“…EE of tilmicosin ranged from 22% to 57% and release rate showed agreement with the increased matrix porosity and swelling behavior of biopolymers. 25 When effects of changes in the geometry of wet beads can be neglected, such as those caused by erosion or swelling, the release of TPC from the beads may be described using the Fick's second law (Equation 5), that, in spherical polar coordinates renders as:…”

Preparation and Characterization of Aminoglycoside-Loaded Chitosan/Tripolyphosphate/Alginate Microspheres against E. coli

“…Their large specific surface area favors the interaction with target tissues allowing the direct treatment application directly to tissues, rather than delivery via bodily fluids, keeping the antibiotic effectiveness even if a lower dose is administrated. In this sense, although both synthetic and natural polymers have been employed to obtain microspheres for controlled-release drug delivery [ 12 , 13 , 14 , 15 ], polysaccharide-based ones in their wide diversity have constituted an important research line in recent years, due to their diverse bioactive attributes as well as other functional properties (biocompatibility, stability, etc.) [ 16 ].…”