Interactions of surfactants in nonionic/anionic reverse hexagonal mesophases and solubilization of α-chymotrypsinogen A

In an attempt to form H_II mesophases at room temperature we prepared lyotropic liquid crystals with two surfactants of the same lipophilic tails (glycerol monooleate, GMO, and oleyl lactate, OL) but differing in the size and charge of the headgroups.Increasing OL concentration significantly affected the hydration of the headgroups and subsequently the lipids packing. At low OL content the cubic mesophase was formed, while at higher OL contents the formation of hexagonal mesophase was favored. It was assumed that OL competed on the water binding, tuning the headgroups’ curvature and the packing parameter inducing the formation of reverse hexagonal mesophase. It was detected that cubic mesophase transformed upon heating to hexagonal structures. The hexagonal mesophases, which were formed both immediately after preparation and after aging, remained stable at elevated temperatures.α-Chymotrypsinogen was solubilized into the obtained LLCs at relatively high concentration (up to 1 wt%). The lattice parameter of the host LLCs exhibited a decrease as a function of the protein content. This process was assigned to partial dehydration of the GMO polar moieties in favor to CTA hydration.Generally speaking, the present study indicated that adding anionic to nonionic lipid is highly beneficial to gain additional compositional and structural characteristics of LLCs.     

Effect of sodium diclofenac loads on mesophase components and structure

We studied the effect of a model electrolytic drug on intermolecular interactions, conformational changes, and phase transitions in structured discontinuous cubic QL lyotropic liquid crystals. These changes were due to competition with hydration of the lipid headgroups. Structural changes of the phase induced by solubilization loads of sodium diclofenac (Na-DFC) were investigated by directly observing the water, ethanol, and Na-DFC components of the resulting phases using 2H and 23Na NMR. Na-DFC interacted with the surfactant glycerol monoolein (GMO) at the interface while interfering with the mesophase curvature and also competed with hydration of the surfactant headgroups. Increasing quantities of solubilized Na-DFC promoted phase transitions from cubic phase (discontinuous (QL) and bicontinuous (Q)) into lamellar structures and subsequently into a disordered lamellar phase. Quadrupolar coupling of deuterated ethanol by 2H NMR showed that it is located near the headgroups of the lipid and apparently is hydrogen bonded to the GMO headgroups. A phase transition between two lamellar phases (L alpha to L alpha*) was seen by 23Na NMR of Na-DFC at a concentration where the characteristics of the drug change from kosmotropic to chaotropic. These findings show that loads of solubilized drug may affect the structure of its vehicle and, as a result, its transport across skin-blood barriers. The structural changes of the mesophase may also aid controlled drug delivery.     

Interactions of biomacromolecules with reverse hexagonal liquid crystals: drug delivery and crystallization applications

Recently, self-assembled lyotropic liquid crystals (LLCs) of lipids and water have attracted the attention of both scientific and applied research communities, due to their remarkable structural complexity and practical potential in diverse applications. The phase behavior of mixtures of glycerol monooleate (monoolein, GMO) was particularly well studied due to the potential utilization of these systems in drug delivery systems, food products, and encapsulation and crystallization of proteins. Among the studied lyotropic mesophases, reverse hexagonal LLC (H(II)) of monoolein/water were not widely subjected to practical applications since these were stable only at elevated temperatures. Lately, we obtained stable H(II) mesophases at room temperature by incorporating triacylglycerol (TAG) molecules into the GMO/water mixtures and explored the physical properties of these structures. The present feature article summarizes recent systematic efforts in our laboratory to utilize the H(II) mesophases for solubilization, and potential release and crystallization of biomacromolecules. Such a concept was demonstrated in the case of two therapeutic peptides-cyclosporin A (CSA) and desmopressin, as well as RALA peptide, which is a model skin penetration enhancer, and eventually a larger macromolecule-lysozyme (LSZ). In the course of the study we tried to elucidate relationships between the different levels of organization of LLCs (from the microstructural level, through mesoscale, to macroscopic level) and find feasible correlations between them. Since the structural properties of the mesophase systems are a key factor in drug release applications, we investigated the effects of these guest molecules on their conformations and the way these molecules partition within the domains of the mesophases. The examined H(II) mesophases exhibited great potential as transdermal delivery vehicles for bioactive peptides, enabling tuning the release properties according to their chemical composition and physical properties. Furthermore, we showed a promising opportunity for crystallization of CSA and LSZ in single crystal form as model biomacromolecules for crystallographic structure determination. The main outcomes of our research demonstrated that control of the physical properties of hexagonal LLC on different length scales is key for rational design of these systems as delivery vehicles and crystallization medium for biomacromolecules.     

Soft matter dispersions with ordered inner structures, stabilized by ethoxylated phytosterols

This paper describes the formation and characterization of liquid crystalline dispersions based on the hexagonal phase of GMO/tricaprylin/water. As a stabilizer of the soft particles dispersed in the aqueous phase, a non-ionic, non-polymeric surfactant—ethoxylated phytosterol with 30 oxyethylene units (PhEO) was utilized. In contrast to Pluronic copolymers, normally utilized in the stabilization of liquid crystalline dispersions with ordered inner structure, use of such non-polymeric surfactant is not a common practice in this field. We revealed how properties of these particles, such as internal structure, size, and stability, can be rationally modified by the concentration of the stabilizing agent and processing conditions. The physical stability of the hexosomes was further examined by the LUMiFuge technique.Structural effect of PhEO solubilization on the properties of the bulk H_II mesophase system showed that phase behavior was greatly influenced following phase transitions: H_II → H_II + cubic → cubic + L_α → L_α. The decrease of hydrogen bonding of the hydroxyl and carbonyl groups of monoolein with water and simultaneous hydration of EO groups of PhEO appeared to be important for the observed behavior. The use of PhEO as a dispersant resulted in a soft matter multi-phase water dispersion with bimodal distribution of the particle population. Effective stabilization of hexosomes was obtained in an extremely narrow concentration range of PhEO (0.1–0.2 wt%), coexisting with small vesicles and disordered particles. At higher PhEO content, particles had disordered inner structure, and unilamellar and multilamellar vesicles, at the expense of hexosomes in consequence of incorporation of the dispersant into the hexosome structure. PhEO was found to induce lamellar phase formation, introducing disorder into the hexagonal LLC and reducing their domain size.Finally, hexosomes were evaluated as delivery vehicles for the therapeutic peptide desmopressin. Sustained release of this drug was observed during the first 10 h; however, permeation drastically increased in the 10–24 h range.     

On structural transitions in a discontinuous micellar cubic phase loaded with sodium diclofenac

An intermediate mesophase of lyotropic liquid crystalline structure from the ternary mixtures of glycerol monooleate, water, and ethanol was recently characterized in our lab. This mesophase, termed Q(L), consists of discrete discontinuous micelles arranged in a cubic array. The Q(L) phase can solubilize very significant loads of water-insoluble anti-inflamatory drug sodium diclofenac (Na-DFC). Close examination of the internal structures of the lyotropic liquid structure upon increasing the solubilization loads reveals the existence of three structural transitions controlled by the Na-DFC levels. Up to 0.4 wt% Na-DFC, the Q(L) structure remains intact with some influence on the hydration of the headgroups and on the intermicellar forces. However, at 0.8 to 1.2 wt% Na-DFC, the discontinuous micellar cubic phase is transformed into a more condensed mesophase of a bicontinuous cubic phase. At > or =1.2 wt% Na-DFC, the cubic phase is converted into a lamellar phase (L(alpha)). Within 5.5 to 7.3 wt% Na-DFC the mesophase is progressively transformed into a less ordered lamellar structure. At 12 wt% Na-DFC crystals tend to precipitate out. At low Na-DFC concentrations the drug behaves like a lyotropic or kosmotropic salt and can salt-out the surfactant from its water layer, but at higher levels it behaves like a hydrotropic, chaotropic salt and can salt-in the surfactant. The Na-DFC location and position within the interface as well as its polarization and partial ionization are strongly affected by its solubilization contents and the structure that it is inducing. In the cubic phase the drug is located less close to the hydration layer while once transition occurs it is exposed more to the water layer and the surfactant headgroups.     

New Insights into the Jahn–Teller Effect through ab initio Quantum-Mechanical/Molecular-Mechanical Molecular Dynamics Simulations of CuII in Water

The Cu^II hydration shell structure has been studied by means of classical molecular dynamics (MD) simulations including three-body corrections and hybrid quantum-mechanical/molecular-mechanical (QM/MM) molecular dynamics (MD) simulations at the Hartree–Fock level. The copper(II ) ion is found to be six-fold coordinated and [Cu(H₂O)₆]²⁺ exhibits a distorted octahedral structure. The QM/MM MD approach reproduces correctly the experimentally observed Jahn–Teller effect but exhibits faster inversions (<200 fs) and a more complex behaviour than expected from experimental data. The dynamic Jahn–Teller effect causes the high lability of [Cu(H₂O)₆]²⁺ with a ligand-exchange rate constant some orders of magnitude higher than its neighbouring ions Ni^II and Zn^II. Nevertheless, no first-shell water exchange occurred during a 30-ps simulation. The structure of the hydrated ion is discussed in terms of radial distribution functions, coordination numbers, and various angular distributions and the dynamical properties as librational and vibrational motions and reorientational times were evaluated, which lead to detailed information about the first hydration shell. Second-shell water-exchange processes could be observed within the simulation time scale and yielded a mean ligand residence time of ≈20 ps.     

A bis‐copper(II)–[d‐βVal3,7]ascidiacyclamide complex enveloping two square pyramids and sharing an apex atom from a carbonate anion

The four azole rings place structural restrictions on ascidiacyclamide (ASC). As a result, the structure of ASC exists in an equilibrium between two major forms (i.e. folded and square). [d ‐βVal^3,7]Ascidiacyclamide (βASC) was synthesized by replacing two d ‐Val‐Thz (Val is valine and Thz is thiazole) blocks with d ‐β‐Valine (D‐βVal‐Thz). This modification expands the peptide ring; the original 24‐membered macrocycle of ASC becomes a 26‐membered ring. Circular dichroism (CD) spectra showed that, in solution, the structural equilibrium is maintained with βASC, but the folded form is dominant. A copper complex was prepared, namely [[d ‐βVal^3,7]ascidiacyclamide(2?)]aqua‐μ‐carbonato‐dicopper(II) monohydrate, [Cu₂(C₃₈H₅₄N₈O₆S₂)(CO₃)(H₂O)]·H₂O, to determine the effect of the change in ring size on the coordinated structure. The obtained bis‐Cu^II–βASC complex contains two water molecules and a carbonate anion. Two Cu^II ions are chelated by three N‐donor atoms of two Thz–Ile–Oxz (Ile is isoleucine and Oxz is oxazoline) units. An O atom of the carbonate anion bridges two Cu^II ions, forming two square pyramids. These features are similar to the previously reported structure of the Cu^II–ASC complex, but the two pyramids are enveloped inside the peptide and share one apex. In the Cu^II–ASC complex, the apex of each square pyramid is an O atom of a water molecule, and the two pyramids are oriented toward the outside of the peptide. The incorporated β‐amino acids of βASC make the space inside the peptide large enough to envelop the two square pyramids. The observed structural changes in the bis‐Cu^II–βASC complex arising from ring expansion are particularly interesting in the context of the previously reported structure of the Cu^II–ASC complex.     

The catanionic system dodecyltrimethylammonium hydroxide–n-dodecanephosphonic acid–water. Triangular phase diagram

 The triangular phase diagram of the system dodecyltri-methylammonium hydroxide (DTAOH)–dodecanephosphonic acid (H₂DP)–water was studied by several techniques. The DTAOH-rich zone could not be studied because DTAOH decomposed when it was dried. Pure H₂DP only forms lamellar mesophases with water. The inclusion of DTAOH in the system produces the appearance of cubic and hexagonal mesophases. The gradual increase in DTAOH proportion lead to the gradual reduction in the existence of the lamellar mesophase domain, and increase of the hexagonal liquid crystal domain. At high DTAOH content, the lamellar mesophase disappeared. This behavior was explained by the gradual destruction of the hydrogen-bonded structure in the polar headgroup layer of liquid crystal aggregates. H₂DP-rich anhydrous crystals were triclinic. Received: 8 September 1997 Accepted: 17 February 1998     

Transitions induced by solubilized fat into reverse hexagonal mesophases

Lyotropic liquid crystals of glycerol monooleate (GMO) and water binary mixtures have been extensively studied and their resemblance to human membranes has intrigued many scientists. Biological systems as well as food mixtures are composed of lipids and fat components including triacylglycerols (TAGs, triglycerides) that can affect the nature of the assembly of the mesophase. The present study examines the effect of TAGs of different chain lengths (C(2)-C(18)) at various water/GMO compositions, on phase transitions from lamellar or cubic to reverse hexagonal (L(alpha)-H(II) and Q-H(II)). The ability of the triglycerides to promote the formation of an H(II) mesophase is chain length-dependent. It was found that TAG molecules with very short acyl chains (triacetin) can hydrate the head groups of the lipid and do not affect the critical packing parameter (CPP) of the amphiphile; therefore, they do not affect the self-assembly of the GMO in water, and the mesophase remains lamellar or cubic. However, TAGs with medium chain fatty acids will solvate the tails of the lipid, and will affect the CPP of the GMO, and transform the lamellar or cubic phases into hexagonal mesophase. TAGs with long chain fatty acids are very bulky, not very miscible with the GMO, and therefore, kinetically are very slow to solvate the lipid tails of the amphiphile and are difficult to accommodate into the lipophilic parts of the GMO. Their effect on the transitions from a lamellar or cubic phase to hexagonal is detected only after months of equilibration. In order to enhance the effect of the TAG on the phase transitions in the GMO/triglyceride/water systems, temperature and electrolytes effects were examined. In the presence of short and medium chain triglycerides, increasing temperature caused a transition from lamellar or hexagonal to L(2) phase (highest CPP value). However, in the presence of long chain TAGs, increasing temperature to ca. 40 degrees C caused a formation of H(II) mesophase. In addition, it was found that in tricaprylin/GMO/water systems, the increase in temperature caused a decrease in the lattice parameter. The effect of NaCl on the H(II) mesophase revealed interesting results. At low concentration of tricaprylin (5 wt%), the addition of only 0.1 wt% of NaCl was sufficient to cause the formation of well-defined H(II) mesophase, while further addition of electrolyte increased the hexagonal lattice parameters. At higher TAGs concentrations (10 wt%), addition of electrolyte resulted in the formation of H(II) with modifications of the lattice parameter. All the examined effects were more pronounced with increasing water content.     

Highly Efficient Copper(II) Ion Sorbents Obtained by Calcium Carbonate Mineralization on Functionalized Cross‐Linked Copolymers

A new type of Cu^II ion sorbents is presented. These are obtained by CaCO₃ mineralization from supersaturated solutions on gel‐like cross‐linked polymeric beads as insoluble templates. A divinylbenzene–ethylacrylate–acrylonitrile cross‐linked copolymer functionalized with weakly acidic, basic, or amphoteric functional groups has been used, as well as different initial inorganic concentrations and addition procedures for CaCO₃ crystal growth. The morphology of the new composites was investigated by SEM and compared to that of the unmodified beads, and the polymorph content was established by X‐ray diffraction. The beads, before and after CaCO₃ mineralization, were tested as sorbents for Cu^II ions. The newly formed patterns on the bead surface after Cu^II sorption were observed by SEM, and the elemental distribution on the composites and the chemical structure of crystals after interaction with Cu^II were investigated by EDAX elemental mapping and by FTIR‐ATR spectroscopy, respectively. The sorption capacity increased significantly after CaCO₃ crystals growth on the weak anionic bead surface (up to 1041.5 mg Cu^II/g sample) compared to that of unmodified beads (491.5 mg Cu^II/g sample).     

立体异构单萜醇油酸酯的制备及促透活性评价

本文以互为立体异构体的香叶醇(GER)、橙花醇(NER)为先导化合物,采用酰氯酯化法合成油酸香叶醇酯(GER-dC18)、油酸橙花醇酯(NER-dC18),并考察GER、NER、GER-dC18、NER-dC18作为促透剂对多奈哌齐(DNP)的促透活性差异。通过体外释放试验、红外光谱法和分子模拟技术初步探究其促透机制,结果发现,所选用促透剂不仅能够促进DNP从压敏胶中释放,而且能够作用于角质层脂质及角蛋白并促进水合作用来降低角质层的屏障功能,从而增加DNP的经皮透过。其中,(E)构型的GER-dC18对DNP具有最优的促透效果,有望为经皮制剂的开发提供关键的辅料。     

Structural properties of lecithin based reverse hexagonal (HII) liquid crystals and in vitro release of dihydromyricetin

Dihydromyricetin (DMY) was encapsulated to lecithin based reverse hexagonal (H_II) liquid crystals to improve its solubility limitation. PEG 400 was used as the representative oil phase. The H_II mesophases were identified by means of polarized light microscopy (POM) and small angle X-ray scattering (SAXS). The DMY was solubilized in interface layer inferred from the increase of the interfacial area of per surfactant a_s and the infrared spectra. The hexagonal samples showed highly elastic Maxwell properties and shear thinning properties indicated by their rheological spectra. Moreover with the decrease of PEG 400 content, the internal structure of samples apparently becomes more stable, as indicated by the increase in the storage and loss moduli and the decrease in a_s. Oleic acid enhances the viscoelasticity of sample and increases the release stability for DMY under acidic conditions. The in vitro release of DMY in H_II matrices showed that carriers have an ideal sustained release effect. The release of DMY was controlled by concentration diffusion.     

Tween 80-based mixed micelles as felodipine carriers in aqueous medium

UV spectroscopy, precise turbidimetry, and refractometry are employed to measure the solubilization of the lipophilic compounds felodipine (F) (drug) and nonionic surfactants glyceryl monooleate (GMO) and glyceryl monolaurate (GML) (efficient promoters of skin permeability (enhancers)) in aqueous solutions of Tween 80 (Tw). An increase in the concentration of Tw makes it possible to enhance the solubility of the drug by a factor of 10²–10³ and above as compared to F solubility in water. The effect becomes stronger in the presence of an enhancer. The following properties of Tw + F, Tw + GMO, Tw + GML, Tw + GMO + F, and Tw + GML + F micelles are studied: the aggregation numbers of the components, localization of solubilizates, diffusion coefficients, sizes, and degrees of hydration. Experimental data on the kinetics of drug mass transfer by micelles are in good agreement with the calculations performed within the framework of diffusion theory. Tw-based mixed micelles are found to be efficient carriers of F and enhancers in aqueous media, which is of importance for the creation of systems for delivery of lipophilic drugs in a bioavailable form.     

Titanium-rich highly ordered mesoporous silica synthesized by using a mixed surfactant system

A new titanium-rich highly ordered 2-D hexagonal mesoporous titanium silicate has been synthesized using a mixture of cationic (cetyltrimethylammonium bromide, CTAB) and non-ionic (Brij-35, C₁₂H₂₅-(OC₂H₄)₂₃-OH, a polyether and aliphatic hydrocarbon chain surfactant) mixed surfactant system as the supramolecular structure directing agent (SDA) in the presence of tartaric acid (TA) as a mineralizer of Ti(IV). XRD, N₂ adsorption and TEM data suggested the presence of mesophase with hexagonal pore arrangements and the UV-visible, FT IR and XPS studies suggested the incorporation of mostly tetrahedral titanium (IV) species in the highly ordered silica network. This mesoporous titanium silicate material showed excellent catalytic activity and selectivity in the epoxidation of styrene using dilute aqueous H₂O₂ as oxidant.     

Grafting copolymerization of N,N-dimethyacrylaminoethylmethacrylate (DMAEMA) onto preirradiated polypropylene films

Grafting copolymerization of dimethylaminoethylmethacrylate (DMAEMA) onto preirradiated polypropylene (PP) films was studied. PP samples were irradiated by electron beam in air. The effects of co-solvent system of ethanol/water (EtOH/H₂O), absorbed dose, monomer concentration, reaction time, and reaction temperature on the degree of grafting were determined. The grafted sample films were investigated by Fourier transform infrared (FTIR) spectroscopy in the attenuated total reflectance mode (ATR).     

CuII Coordination Chemistry of Patellamide Derivatives: Possible Biological Functions of Cyclic Pseudopeptides

Two synthetic derivatives of the naturally occurring cyclic pseudooctapeptides patellamide A–F and ascidiacyclamide, that is, H₄pat², H₄pat³, as well as their Cu^II complexes are described. These cyclic peptide derivatives differ from the naturally occurring macrocycles by the variation of the incorporated heterocyclic donor groups and the configuration of the amino acids connecting the heterocycles. The exchange of the oxazoline and thiazole groups by dimethylimidazoles or methyloxazoles leads to more rigid macrocycles, and the changes in the configuration of the side chains leads to significant differences in the folding of the cyclic peptides. These variations allow a detailed study of the various possible structural changes on the chemistry of the Cu^II complexes formed. The coordination of Cu^II with these macrocyclic species was monitored by high‐resolution electrospray mass spectrometry (ESI‐MS), spectrophotometric (UV/Vis) and circular dichroic (CD) titrations, and electron paramagnetic resonance (EPR) spectroscopy. Density functional theory (DFT) calculations and molecular mechanics (MM) simulations have been used to model the structures of the Cu^II complexes and provide a detailed understanding of their geometric preferences and conformational flexibility. This is related to the Cu^II coordination chemistry and the reactivity of the dinuclear Cu^II complexes towards CO₂ fixation. The variation observed between the natural and various synthetic peptide systems enables conclusions about structure–reactivity correlations, and our results also provide information on why nature might have chosen oxazolines and thiazoles as incorporated heterocycles.     

The role of glycerol and phosphatidylcholine in solubilizing and enhancing insulin stability in reverse hexagonal mesophases

The potential of reverse hexagonal mesophases based on monoolein (GMO) and glycerol (as cosolvent) to facilitate the solubilization of proteins, such as insulin was explored. H(II) mesophases composed of GMO/decane/water were compared to GMO/decane/glycerol/water and GMO/phosphatidylcholine (PC)/decane/glycerol/water systems. The stability of insulin was tested, applying external physical modifications such as low pH and heat treatment (up to 70°C), in which insulin is known to form ordered amyloid-like aggregates (that are associated with several neurodegenerative diseases) with a characteristic cross β-pleated sheet structure. The impact of insulin confinement within these carriers on its stability, unfolding, and aggregation pathways was studied by combining SAXS, FTIR, and AFM techniques. These techniques provided a better insight into the molecular level of the "component interplay" in solubilizing and stabilizing insulin and its conformational modifications that dictate its final aggregate morphology. PC enlarged the water channels while glycerol shrank them, yet both facilitated insulin solubilization within the channels. The presence of glycerol within the mesophase water channels led to the formation of stronger hydrogen bonds with the hosting medium that enhanced the thermal stability of the protein and remarkably affected the unfolding process even after heat treatment (at 70°C for 60 min).     

Thermally induced fluid reversed hexagonal (H(II)) mesophase

In the present study we characterized the microstructures of the Lc and HII phases in a glycerol monooleate (GMO)/tricaprylin (TAG)/water mixture as a function of temperature. We studied the factors that govern the formation of a low-viscosity HII phase at relatively elevated temperatures (>35 degrees C). This phase has very valuable physical characteristics and properties. The techniques used were differential scanning calorimetry (DSC), wide- and small-angle X-ray scattering (WAXS and SAXS, respectively), NMR (self-diffusion and (2)H NMR), and Fourier transform infrared (FTIR) spectroscopies. The reverse hexagonal phase exhibited relatively rapid flow of water in the inner channels within the densely packed cylindrical aggregates of GMO with TAG molecules located in the interstices. The existence of two water diffusion peaks reflects the existence of both mobile water and hydration water at the GMO-water interface (hydrogen exchange between the GMO hydroxyls and water molecules). Above 35 degrees C, the sample became fluid yet hexagonal symmetry was maintained. The fluidity of the HII phase is explained by a significant reduction in the domain size and also perhaps cylinder length. This phenomenon was characterized by higher mobility of the GMO, lower mobility of the water, and a significant dehydration process.     

Microstructure and thermal analysis of lithium ferrite pre-milled in a high-energy ball mill

The synthesis and thermal and spectroscopic studies of a new Co^II–Fe^III heteropolynuclear coordination compound are presented. The in situ oxidation product of ethylene glycol plays the role of ligand. Under specific working conditions, the reaction of ethylene glycol with Fe^III and Co^II nitrates in dilute acid solutions occurs with the oxidation of the former to glyoxylic acid, coordinated to the Co^II and Fe^III cations as glyoxylate anion (C₂H₂O₄ ^2?), with simultaneous isolation of the heteropolynuclear coordination compound. In order to separate and identify the ligand, the synthesized coordination compound, having the composition formula Co₄Fe₁₀(L)₉(OH)₂₀(H₂O)₃₂·14H₂O, where L is the glyoxylate anion, has been treated with R–H cationite (Purolite C-100). After the retention of the metal cations, the resulting glyoxylic acid was confirmed by measuring its physical constants, by specific reactions and through spectroscopic methods. The synthesized coordination compound was characterized by physical–chemical analysis, electronic spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and thermal analysis. Cobalt ferrite impurified with ferric oxide was obtained following the thermal decomposition of Co^II–Fe^III polyhydroxoglyoxylate. The oxides obtained through thermolysis were studied by FTIR, XRD, scanning electron microscopy (SEM) and elemental analysis.