Zinc monoglycerolate — A slow-release source of therapeutic zinc: Solubilization by endogenous ligands

Abstract

A combination of 65Zn-tracer determinations, oxidative analyses for glycerol, and a bioassay for uncomplexed Zn2+ have shown that: (i) zinc monoglycerolate (ZMG) dissolves in aqueous salt solutions/physiological media by dissociation into zinc ions and glycerol, but the rate and extent of ZMG dissolution depend upon pH, and/or concentration and complexing efficiency of zinc-ligands; (ii) under physiological conditions certain ligands present in skin and blood (e.g. citrate, lactate, albumin, histidine, glutathione and other thiols and, to a lesser extent, amino acids) accelerate ZMG dissolution; and (iii) there is a general correlation between the conditional stability constants (pH 7.3, 25 degrees C) of zinc-ligand complexes and the ability of given ligands to (a) solubilize ZMG in vitro and (b) mask the irritancy of Zn2+ in vivo. These observations indicate a mechanism for the transformation of ZMG applied transdermally or subcutaneously, to bioactive zinc (anti-arthritic nutritional supplement, etc.).

RETRACTED: Preparation and characterization of zinc glycerolate: UV protection, biological activity and permeation study

“…The empirical formula for zinc glycerolate complex is (C 3 H 6 O 3 Zn) x [8]. It is proposed in a myriad of applications from cosmetics [8], nutrition as dietary supplement [9,16] to bonding agent in plastic or rubber materials [10]; but most notably in pharmaceutical [8,9,[18][19][20][21].…”

Synthesis of zinc oxide nanoparticles elaborated by microemulsion method

“…When Zn 2+ ions are incorporated ion exchange reaction takes place and finally Na + replaces with Zn 2+ in the dispersed micelles [1]. The Zn-Gly complex acting as a precursor for ZnO formation was synthesized in the presence of NaOH, because the reaction between zinc acetate and glycerol is much faster in basic environment and as Zn-Gly decomposes in acidic solutions [31]. In other words, NaOH was used as electrolyte serving for glycerol stabilization in n-heptane and provides rigidity for the droplet interfacial film and so the stability of droplet size [32].…”

Controlled production of ZnO nanoparticles from zinc glycerolate in a sol–gel silica matrix

“…It also appears that the particles are not spherical, but rather elongated, which may partly explain why the observed particle size does not agree very well with that predicted using Scherrer's equation. The reported macroscopic crystals of zinc glycerolate are plate-like, showing flat (100) faces and having an elongated hexagonal shape [48,51]. If the crystals are oriented appropriately, the HRTEM image of the nanoparticles produced in microemulsions also show an elongated hexagonal shape (see trial hexagons inserted in Fig.…”

“…Zn-Gly is produced in the presence of NaOH, because the reaction between zinc acetate and glycerol is much faster in alkaline solutions, and also because Zn-Gly decomposes in acidic solutions [51]. It is rather surprising that Zn-Gly forms readily at a temperature of 40 • C in the microemulsion droplets, since its synthesis is usually carried out at temperatures between 120 and 300 • C by decomposition of ZnO or Zn(OH) 2 in the presence of glycerol [48][49][50][51].…”

“…It is rather surprising that Zn-Gly forms readily at a temperature of 40 • C in the microemulsion droplets, since its synthesis is usually carried out at temperatures between 120 and 300 • C by decomposition of ZnO or Zn(OH) 2 in the presence of glycerol [48][49][50][51]. XRD patterns presented in When zinc acetate is used as the zinc source, the pattern contains some small additional peaks (at 2θ equal to 5.8 • , 12.5 • , 14.3 • , and 22.2 • , identified in the pattern with filled circles), which may be attributed to zinc acetate hydrate (PDF number 33-1464).…”