Synergistic effect of divalent cations in improving technological properties of cross-linked alginate beads.
Gelling solution parameters are some of the most important variables in ionotropic gelation and consequently influence the technological characteristics of the product. To date, only a few studies have focused on the simultaneous use of multiple cations as gelling agents. With the aim to deeply explore this possibility, in this research we investigated the effect of two divalent cations (Ca2+and Zn2+) on alginate beads formation and properties. Alginate beads containing prednisolone (P) as model drug were prepared by prilling technique. The main critical variables of the ionotropic gelation process i.e. composition of the aqueous feed solutions (sodium alginate and prednisolone concentration) and cross-linking conditions (Ca2+, Zn2+or Ca2++Zn2+), were studied. The obtained beads were characterized and their in vitro release performances were assessed in conditions simulating the gastrointestinal environment. Results evidenced a synergistic effect of the two cations, affecting positively both the encapsulation efficiency and the ability of the alginate polymeric matrix to control the drug release. A Ca2+/Zn2+ratio of 4:1, in fact, exploited the Ca2+ability of establish quicker electrostatic interactions with guluronic groups of alginate and the Zn2+ability to establish covalent-like bonds with carboxylate groups of both guluronic and mannuronic moieties of alginate.
Department of Pharmacy, University of Salerno, I-84084 Fisciano, SA, Italy; PhD Program in Drug Discovery and Development, University of Salerno, I-84084 Fisciano, SA, Italy.
Andrea
A
Cerciello
Department of Pharmacy, University of Salerno, I-84084 Fisciano, SA, Italy.
Pasquale
P
Del Gaudio
Department of Physics "E.R. Caianiello", University of Salerno, I-84084 Fisciano, SA, Italy.
Veronica
V
Granata
Department of Pharmacy, University of Salerno, I-84084 Fisciano, SA, Italy.
Marina
M
Sala
Department of Pharmacy, University of Salerno, I-84084 Fisciano, SA, Italy.
Rita P
RP
Aquino
Department of Pharmacy, University of Salerno, I-84084 Fisciano, SA, Italy. Electronic address: paorusso@unisa.it.
Paola
P
Russo
D000464:Alginates / Q000737:chemistry*; D002413:Cations, Divalent / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D065546:Drug Liberation; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D007700:Kinetics; D008863:Microspheres
D000464:Alginates; D002413:Cations, Divalent; D004337:Drug Carriers; D006603:Hexuronic Acids; D020723:Glucuronic Acid
Alginate beads; Controlled release; Gelling cations; Ionotropic gelation; Synergic effect