Preparation and characterization of chitosan based micro networks: Transposition to a prilling process

Abstract

Beads of chitosan (CS) crosslinked network and of chitosan/poly(ethylene oxide) (CS/PEO) semi-interpenetrating network (semi-IPN) were prepared by a dropping technique and characterized. PEO content in the beads of semi-IPN was determined by gel permeation chromatography. CS crosslinking ratio was evaluated qualitatively by ATR-FTIR spectroscopy and quantitatively by UV spectrophotometry. After drying in a fluidized bed apparatus, a monodisperse population of well individualized, spherical, and smooth particles was obtained. It was shown that bead collapsus during the drying stage was avoided thanks to the chemical crosslinking of CS chains. By the prilling, or laminar jet break-up technology, production at a larger scale was also achieved. This process allowed the formation of a row of well calibrated drops of polymer solution under the influence of a vibration. Polymer solution characteristics, particularly viscosity, constituted a critical factor in the feasibility of the prilling process. Transposition of the formulation was managed through the optimization of process parameters such as vibration frequency, amplitude, and flow rate.

Self-Diffusion in Chitosan Networks: From a Gel−Gel Method to Fluorescence Recovery after Photobleaching by Fringe Pattern

“…It was not possible to obtain a good dissolution for chitosan concentration higher than 2% with the studied molecular weight (1.0 × 10 6 g/mol). Then all diffusion measurements were performed at a chitosan concentration of 1.5 wt % because this concentration was already used in a previous work on the preparation of micro network of chitosan by a dropping process in view to obtain a new drug carrier excipient for the oral route …”

“…Then all diffusion measurements were performed at a chitosan concentration of 1.5 wt % because this concentration was already used in a previous work on the preparation of micro network of chitosan by a dropping process in view to obtain a new drug carrier excipient for the oral route. 36 Caffeine preliminarily solubilized in 0.1 mol/L acetic acid aqueous solution was added to the chitosan solution (concentration of 2 wt %) to obtain a solution of 1.5 wt % of chitosan at pH ) 4 with a final caffeine concentration of 0.7 wt %. FITC-dextran preliminarily solubilized in water was added to the 2 wt % chitosan solution to obtain a solution of 1.5 wt % of chitosan at pH ) 5 with a dextran concentration of 0.1 wt %.…”

Development of alumina microspheres with controlled size and shape by vibrational droplet coagulation

“…Changing the alginate type increased the overall viscosity in the whole measured shear rate range. The shear rate at the nozzle depends on the following process parameters and can be estimated by the method described by Martinez et al [37]. The shear rate 𝛾̇ is calculated from the superimposed flow rate Q (m³/s) and the nozzle radius R (m):…”

On Prilling of Hydrophilic Microgels in Lipid Dispersions Using Mono‐N‐Carboxymethyl Chitosan for Oral Biologicals Delivery

“…Many polymers have been used with the prilling technique, such as alginate, chitosan, poly(lactide‐co‐glycolide), or even polymeric mixtures . Especially chitosan, a natural linear polysaccharide composed of d ‐glucosamine and N‐acetyl‐ d ‐glucosamine, displays interesting properties for drug delivery .…”