Preparation of regular sized Ca-alginate microspheres using membrane emulsification method

Abstract

Monodisperse Ca-alginate microspheres were prepared using the membrane emulsification method. Three ionic types of drugs (anionic, cationic and non-ionic) were incorporated into the microspheres, and the effects of sodium alginate concentration and the pressure applied during the dispersing process on the properties of the microspheres were examined. Monodisperse microspheres were obtained when the concentration of alginate solution was 2 wt% and the pressure applied was 0.4 x 10(5) Pa. The mean size of microspheres was approximately 4 microm. Lidocaine x HCl (cationic), sodium salicylate (anionic) and 4-acetamidophenol (non-ionic) were selected as ionic model drugs and included in the alginate microspheres. Lidocaine x HCl (cationic drug) release was more retarded than that of the anionic drug, because of the electrostatic attraction between the negative charge of the ionized carboxyl group in the alginate chain and the positive charge of the cationic drug. In acidic release medium, a slow release was observed due to the low swelling characteristic and the increased viscosity of alginate, regardless of ionic type of drug.

Survival of alginate-microencapsulated Lacticaseibacillus paracasei under gastrointestinal conditions in models in vitro and in vivo

“…The zeta potential of the microspheres ranged from -11.7 ± 0.05 to -22.0 ± 0.03, and similar mV values from -0.68 to -16 have been reported for alginate microspheres (You et al, 2001;Tello et al, 2015). This potential is the product of the reaction between sodium alginate and calcium chloride at different concentrations.…”

Calcium alginate microcapsule generation on a microfluidic system fabricated using the optical disk process

“…For example, sodium alginate (Na-alginate) is extruded dropwise through a needle into a solution of divalent cations, which induces crosslinking of the guluronic residues of the alginate polymer [11][12][13][14]. The alternative techniques are as follows: (i) atomization (spray-drying) [15,16], (ii) coacervation [17], (iii) emulsification (internal/external gelation) [18][19][20][21] and other methods. However, all of these techniques have well-known drawbacks such as unstable yield, tedious procedures and non-uniform particle sizes with a wide size distribution.…”

Improvement of3Dprinting properties of rose‐sodium alginate heterogeneous gel by adjusting rose material

“…The insoluble behavior of chitosan would prevent the anthocyanin in rose petals from dissolving into alginate gel solution, providing a beneficial effect on the preservation of anthocyanin (Tirtashi et al, 2019). Moreover, the positive charge of chitosan (Guo, Ping, Jiang, Huang, & Tong, 2003) can inhibit the change of anthocyanin structure in the rose even when contact with sodium alginate with a negative charge (You et al, 2001). In summary, by comparing the degradation rate of anthocyanins, it was found that 1% chitosan and peanut oil coatings had a better color protection effect.…”