Lanthanum Carbonate Research Articles

High-gravity-assisted controlled synthesis of lanthanum carbonate for highly-efficient adsorption of phosphate

Algal bloom caused by excessive phosphate is toxic to the ecosystem and human health, and lanthanum carbonate (LC) as an adsorbent is efficient for phosphate removal. Herein, we propose an efficient high-gravity-assisted precipitation method to synthesize LC with polymorphs and various morphologies including amorphous LC (ALC), flower, layer, and rod in a rotating packed bed (RPB) by adjusting reaction temperature, time, and solvent. Compared to traditional stirred tank reactor, the RPB can prepare smaller LC particles with narrower size distribution in a shorter reaction time. Remarkably, the 35 nm ALC with the highest BET surface area (106 m2/g) can remain steady among 6 months of storage and exhibits superior adsorption performances with a high adsorption rate (reaching equilibrium within 1 h) and adsorption capacity (162 mg P/g). Especially, its adsorption capacity per unit time is currently at the leading level reported in the literature. The possible adsorption mechanism reveals that the amorphous state, nanonization and high BET surface area of LC accelerate the dissolution procedure to allow more complete exposure of the intrinsic active sites for ligand exchange and maximize La utilization, resulting in the remarkable improvement of adsorption performance. These findings suggest that amorphous nanoparticles serve as a novel state-of-art candidate toward greatly improved efficiency of ions removal in wastewater.

Effects of Lanthanum Carbonate on Whole-Body Calcium Balance, Vascular Function, and Mineral Metabolites in Adults With CKD 3b-4 and Normophosphatemia

Effects of Lanthanum Carbonate on Whole-Body Calcium Balance, Vascular Function, and Mineral Metabolites in Adults With CKD 3b-4 and Normophosphatemia

The influence of phase purity on the stability of Pt/LaAlO3 catalysts in the aqueous phase reforming of glycerol

Aqueous phase reforming (APR) of waste oxygenates offers the potential for sustainable hydrogen production. However, catalyst stability remains elusive, due to the aggressive hydrothermal conditions employed. Herein, we show that the catalytic performance and stability of Pt supported on LaAlO3 catalysts for glycerol APR is strongly influenced by the phase purity of LaAlO3. Calcination of the support at 700 °C produces the LaAlO3 perovskite phase and an amorphous lanthanum carbonate phase, which can be removed by calcination at higher temperature. Catalysts comprised of phase pure LaAlO3 were notably more active, with a support calcination temperature of 1100 °C resulting in 20.4% glycerol conversion (TOF 686 h−1) in a 2 h batch reaction. Interestingly, all the catalysts, regardless of LaAlO3 phase purity, eventually transform into Pt/LaCO3OH-AlO(OH) during reaction, but only in the presence of evolved carbon dioxide, itself produced from glycerol reforming. Studies using simulated reaction products showed that organic acid products (lactic acid), in the absence of CO2, facilitated La leaching and loss of crystallinity. A carbonate source (CO2) is essential to limit La leaching and form stable Pt/LaCO3OH. Pt supported on LaCO3OH and AlO(OH) are stable and active catalysts during APR reactions. Yet, the rate of perovskite phase decomposition strongly influences the final catalyst performance, with the initially phase impure LaAlO3 decomposing too quickly to facilitate Pt redistribution. LaAlO3 calcined at higher temperatures evolved more slowly and consequently produced more active catalysts.

Crystal structure and spectral characterization of La2(CO3)3 ⋅ 5H2O – an industrially relevant lanthanide carbonate

AbstractThe conversion of La2O3 with HCl, subsequent neutralization and precipitation using (NH4)2CO3 in an industrial process leads to the previously unknown La2(CO3)3 ⋅ 5H2O. The phase was characterized by X‐ray powder diffraction leading to an averaged crystal structure model, thermal analysis, vibrational and optical spectroscopy. La2(CO3)3 ⋅ 5H2O crystallizes in space group Pbca(61) with a=9.0167(4) Å, b=12,842(3) Å, c=9.6331(4) Å and V=1115.4(3) Å3. The structure consists of zig zag layers and a highly disordered interlayer space occupied by water molecules and carbonate anions. Partially occupied water‐related oxygen positions theoretically allow for a flexible hydrate water content La2(CO3)3 ⋅ xH2O, with x ranging from 1.5 to 5.0. Although a strong structural relationship between La2(CO3)3 ⋅ 5H2O and La2(CO3)3 ⋅ 8H2O and similar substance properties were found, the title compound cannot be obtained by partial dehydration of the octahydrate. Instead, both lanthanum carbonate hydrates transform into strongly disordered La2(CO3)3 in a one‐step dehydration process.

Phosphate removal and recovery by lanthanum-based adsorbents: A review for current advances.

Controlling eutrophication and recovering phosphate from water bodies are hot issues in the 21st century. Adsorption is considered to be the best method for phosphate removal because of its high adsorption efficiency and fast removal rate. Among the many adsorbents, lanthanum (La)-based adsorbents have been paid more and more attention due to their strong affinity to phosphorus. This paper reviews research of phosphate adsorption on La-based adsorbents in different La forms, including lanthanum oxide/hydroxide, lanthanum mixed metal oxide/hydroxide, lanthanum carbonate, La3+, La-based metal-organic framework (La-MOF) and La-MOF derivatives. The La-based adsorbents can be loaded on many carriers, such as carbon material, clay minerals, porous silica, polymers, industrial wastes, and others. We find that lanthanum oxide/hydroxide and La3+ adsorbents are mostly studied, while those in the forms of lanthanum carbonate, La-MOF, and La-MOF derivatives are relatively few. The kinetic process of most phosphate adsorption is pseudo-second-order and the isotherm process is in accordance with the Langmuir model. The cost of La-based and other traditional adsorbents was compared. The adsorption mechanisms are categorized as electrostatic attraction, ligand exchange, Lewis acid-base interaction, ion exchange and surface precipitation. Besides, regeneration methods of La-based adsorbents are mainly acid, alkali, and salt-alkali. In addition, the La-based adsorbents after absorbing phosphate can be directly used as a slow-release fertilizer. This review provides a basis for the research on phosphate adsorption by La-based adsorbents. It should be carried out to further develop La-based materials with high adsorption capacity and good regeneration ability. Meanwhile, studies have been conducted on the reuse of phosphate after desorption, which needs more attention in future research.

Sweet Corrosion Inhibition by CO2 Capture.

The most practical and economical way to combat the problems derived from CO2 corrosion (sweet corrosion) is the use of corrosion inhibitors of organic origin. Its main protection mechanism is based on its ability to adsorb on the metal surface, forming a barrier between the metal surface and the aggressive medium. However, despite its excellent performance, its inhibition efficiency can be compromised with the increase in temperature as well as the shear stresses. In this study, the use of an inorganic inhibitor is proposed that has not been considered as an inhibitor of sweet corrosion. The reported studies are based on using LaCl3 as a corrosion inhibitor. Its behavior was evaluated on 1018 carbon steel using electrochemical measurements, such as potentiodynamic polarization curves, open-circuit potential measurements, linear polarization resistance measurements, and electrochemical impedance. The results showed an inhibition efficiency of the sweet corrosion process greater than 95%, and that the inhibition mechanism was different from the classic corrosion process in CO2-free electrolytes. In this case, it was observed that the inhibitory capacity of the La3+ cations is based on a CO2-capture process and the precipitation of a barrier layer of lanthanum carbonate (La2(CO3)3).

Enhanced dry reforming of methane by microwave-mediated confined catalysis over Ni-La/AC catalyst

The dry reforming of methane (DRM) is an attractive technology for CO2 utilization to produce syngas for the production of value-added chemicals and fuels. However, commercialized application of DRM has been limited by the severe temperature conditions required to activate the low energy molecules (CH4 and CO2) and prohibit the formation of coke. Here we report efficient syngas production via methane reforming mediated by the microwave-triggered activation of Lanthanum nickelate (LNO) and carbon deposited on the catalysts could enhance the catalytic performance under microwave irradiation. AC-based materials could reach ∼ 100 % reactant conversion in the microwave-assisted DRM (MW-DRM) process. We have also investigated the reaction mechanism on Ni-La/AC catalysts by using CO2-TPD and in situ DRIFTS analysis. It was observed that lanthanum oxycarbonates were active intermediates for CO2 activation and oxidation of carbonaceous intermediates from methane on the catalyst, thus improving catalytic activity and stability. This catalyst exhibited an advantage of process intensification and reaction stability in the MW-DRM process, in contrast to the conventional heating process.

A rare gastric foveolar-type adenoma with lanthanum deposition in a Helicobacter pylori–uninfected patient

A 53-year-old man undergoing hemodialysis for chronic kidney disease had been taking lanthanum carbonate for the previous 3 years. EGD revealed a 5-mm reddish protruding lesion, with a raspberry-like appearance and white deposits on its surface, in the upper third section of the Helicobacter pylori–uninfected stomach (A). Narrow-band imaging (NBI; Olympus, Tokyo, Japan) along with texture and color enhancement imaging (TXI; Olympus)—assisted endoscopy revealed the presence of white deposits considered to be of lanthanum, as confirmed by different endoscopic results from white opaque substance (WOS), light blue crest (LBC), and white globe appearance (WGA) (B, C).

Evaluation of cerium oxide as a phosphate binder using 5/6 nephrectomy model rat

BackgroundThe number of chronic kidney disease (CKD) patients continues to increase worldwide. CKD patients need to take phosphate binders to manage serum phosphorus concentrations. Currently, several types of phosphate binder, including lanthanum carbonate, are used. However, they each have disadvantages.MethodsIn this study, we evaluated cerium oxide as a new phosphate binder in vitro and in vivo. First, cerium oxide was mixed with phosphoric acid at pH 2.5 or 7.0, and residual phosphoric acid was measured by absorption photometry using colorimetric reagent. Second, cerium oxide was fed to 5/6 nephrectomy model rats (5/6Nx), a well-known renal damage model. All rats were measured food intake, water intake, feces volume, and urine volume, and collected serum and urine were analyzed for biochemical markers.ResultsCerium oxide can adsorb phosphate at acidic and neutral pH, while lanthanum carbonate, which is a one of popular phosphate binder, does not dissolve at neutral pH. Cerium oxide-treatment reduced serum phosphate concentrations of 5/6Nx rats without an increase in serum alanine transaminase levels that would indicate hepatotoxicity, and cerium oxide-treatment maintained serum creatinine and blood urea nitrogen levels, while those of normal 5/6Nx rats increased slightly. ConclusionsThese results suggest that cerium oxide can be a potential phosphate binder. Decreased body weight gain and increased water intake and urine volume in 5/6Nx rats were thought to be an effect of nephrectomy because these changes did not occur in sham operation rats. Additional investigations are needed to evaluate the longer-term safety and possible accumulation of cerium oxide in the body.

Ferric citrate for the treatment of hyperphosphatemia and anemia in patients with chronic kidney disease: a meta-analysis of randomized clinical trials

Background Hyperphosphatemia and anemia, which are common complications of chronic kidney disease (CKD), can independently contribute to cardiovascular events. Several previous studies have found that the iron-based phosphate binder, ferric citrate (FC), could be beneficial to both hyperphosphatemia and anemia. Methods Relevant literature from PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials (CCRCT) and MEDLINE databases were searched up to 21 February 2022, in order to conduct a meta-analysis to investigate the efficacy, safety and economic benefits of ferric citrate treatment in CKD patients with hyperphosphatemia and anemia. The meta-analysis was conducted independently by two reviewers using the RevMan software (version 5.3). Results In total, this study included 16 randomized clinical trials (RCT) involving 1754 participants. The meta-analysis showed that ferric citrate could significantly reduce the serum phosphorus in CKD patients compared to the placebo control groups (MD −1.76 mg/dL, 95% CI (−2.78, −0.75); p = 0.0007). In contrast, the difference between ferric citrate treatment and active controls, such as non-iron-based phosphate binders, sevelamer, calcium carbonate, lanthanum carbonate and sodium ferrous citrate, was not statistically significant (MD − 0.09 mg/dL, 95% CI (−0.35, 0.17); p = 0.51). However, ferric citrate could effectively improve hemoglobin levels when compared to the active drug (MD 0.43 g/dL, 95% CI (0.04, 0.82); p = 0.03) and placebo groups (MD 0.39 g/dL, 95% CI (0.04, 0.73); p = 0.03). According to eight studies, ferric citrate was found to be cost-effective treatment in comparison to control drugs. Most of the adverse events (AE) following ferric citrate treatment were mild at most. Conclusion Collectively, our review suggests that iron-based phosphate binder, ferric citrate is an effective and safe treatment option for CKD patients with hyperphosphatemia and anemia. More importantly, this alternative treatment may also less expensive. Nevertheless, more scientific studies are warranted to validate our findings.

Development of potent non-acylhydrazone inhibitors of intestinal sodium-dependent phosphate transport protein 2b (NaPi2b)

Inhibition of intestinal sodium-dependent phosphate transport protein 2b (NaPi2b), responsible for intestinal phosphate absorption, is considered to reduce serum phosphate levels, making it a promising therapeutic approach for hyperphosphatemia. Previously, we aimed to identify new drugs for hyperphosphatemia treatment and obtained zwitterionic compound 3 (IC50 = 64 nM) as a potent selective inhibitor of intestinal NaPi2b. This small-molecule compound is gut-restricted owing to its almost membrane-impermeable property. However, when compound 3, containing an acylhydrazone structure, is exposed to plasma, it is easily metabolized and likely produces an acetylhydrazine compound. Clinical studies have shown that acetylhydrazine is a risk factor for hepatic toxicity owing to its microsomal metabolism, wherein toxic reactive intermediates are formed.Therefore, in this study, we aimed to obtain potent NaPi2b inhibitors without an acylhydrazone structure to reduce the risk of hepatic toxicity. We developed compound 18, an anilide compound with zwitterionic property having potent phosphate uptake inhibitory activity in vitro (IC50 = 14 nM) and low bioavailability (FaFg = 5.9%). Oral administration of compound 18 in rats showed a reduction in phosphate absorption comparable to that observed with lanthanum carbonate, a clinically effective phosphate binder used in hyperphosphatemia treatment. Moreover, combined administration of compound 18 and lanthanum carbonate resulted in an additive effect on phosphate absorption inhibition in rats. Our findings suggest that combination therapy with lanthanum carbonate and compound 18 will not only provide better treatment outcomes for hyperphosphatemia but also reduce gastrointestinal side effects in patients.

Lanthanum carbonate hydroxide/magnetite nanoparticles functionalized porous biochar for phosphate adsorption and recovery: Advanced capacity and mechanisms study

As the increase of global industrial activities, phosphate from industrial wastes such as sewage sludge has become one of the limiting factors for water eutrophication. Herein, lanthanum carbonate hydroxide (La(CO3)OH)/magnetite (Fe3O4) nanoparticles functionalized porous biochar (La/Fe-NBC) with high phosphate adsorption properties is synthesized through molten salt pyrolysis-coprecipitation-hydrothermal multi-step regulation, and further reveal the related processes and mechanisms. La(CO3)OH functions as active sites for phosphate adsorption, Fe3O4 imparts magnetic properties to the composite substance, also porous biochar (NBC) acts as the carrier to prevent the agglomeration of La(CO3)OH and Fe3O4 nanoparticles. The adsorption process of La/Fe-NBC for phosphate fits to the Pseudo-Second Order and Langmuir model, with the theoretical maximum adsorption capacity up to 99.46 mg P/g. And La/Fe-NBC possesses excellent magnetic field (14.50 emu/g), stability, and selectivity, which enables for efficient multiple recovery and reuse. Mechanistic studies have shown that ligand exchange (inner-sphere complexation) between phosphate and carbonate/hydroxyl groups of La(CO3)OH, and electrostatic attraction play the dominant roles during adsorption process, although susceptible to the solution pH. While co-precipitation is not influenced of pH conditions but with limited contribution to phosphate adsorption. This study may facilitate to optimize the synthesis design of phosphate multi-functional composites for low-carbon and sustainable treatment of industrial phosphate-containing wastes.

ELECTROPHYSICAL PROPERTIES OF NEW NANOSTRUCTURED COPPER-ZINC MANGANITE OF LANTHANUM AND MAGNESIUM

The polycrystalline copper-zinc manganite was synthesized by the solid-phase interaction in the range of 800-1200 °C of oxides of lanthanum (III), copper (II), zinc (II), manganese (III) and magnesium carbonate, thus its nanostructured particles were first obtained by grinding on the vibrating mill “Retsch” (Germany). The X-ray investigations determined that the nanostructured manganite is crystallized in the cubic syngony. On the LCR-7817/827 device(Company «Good Will Instrument Co., Ltd., Taiwan») in the range of 293-483 K at frequencies equal to 1.5 and 10 kHz, the dielectric constantand electrical resistance were investigated and it was found that this compound at 293-353 K has the semiconductorconductivity, at 353-373 K -metal and at 373-483 K -semiconductor conductivity again. The band gap widths were calculated. The permittivity at 483 K reaches gigantic values at all frequencies.Referring to the above, the objective of this paper is to study the temperature dependence of the dielectric constantand the electrical resistance of a new nanostructured copper-zinc manganite of lanthanum and magnesium.

MO734: High Serum Oxalate Concentration Associated with Coronary Artery Calcification and Lanthanum Carbonate in Hemodialysis Patients

Abstract BACKGROUND AND AIMS Oxalate is an organic acid found in abundance in plants and can also be synthesized as a terminal metabolite by the organic acid metabolism systems in humans. As a major excretion pathway of oxalate is urine, serum oxalate (SOx) concentration elevates in end-stage renal disease (ESRD) patients and causes calcium oxalate deposition to tissues. We previously reported that calcium oxalate might be one of the major components of coronary artery calcification (CAC) in ESRD patients; however, the association between SOx and CAC is unknown. This study aimed to demonstrate the relationship between SOx and CAC in haemodialysis patients. METHOD A total of 77 patients undergoing maintenance haemodialysis at a single facility who underwent an atherosclerosis check-up from 2011 to 2012 were enrolled and measured SOx retrospectively in 2021. Of those, 17 extremely outlying SOx patients were excluded, and 60 patients including 42 males were analysed. The median age was 64 (35–85) years, and median dialysis duration was 87.5 (17.1–410) months. Gender, Agastston's CAC score, major artery calcification volume, laboratory data and medications around the atherosclerosis check-up date and new-onset cardiovascular disease (CVD) events and deaths during the 10-year observation period were recorded. A CVD event is defined as an admission due to non-fatal myocardial infarction, coronary artery disease or heart failure. SOx level was measured by the commercial colorimetric oxalate assay kit, and the normal SOx level was 181 µmol/L. RESULTS The median SOx was 267 (221–563) µmol/L and new-onset CVD events, all-cause deaths occurred in 28 (47%) and 22 (37%) patients, respectively. In univariate analysis, SOx was associated with males (r = 0.27, P = 0.03), serum albumin (r = –0.25, P = 0.05), uric acid (r = 0.29, P = 0.02), phosphate (r = 0.26, P = 0.04), alkaline phosphatase (r = –0.28, P = 0.03), lanthanum carbonate (r = 0.32, P = 0.01), major artery calcification volume (r = 0.28, P = 0.03) and CAC score (r = 0.29, P = 0.02). In multivariate regression analysis, SOx was associated with lanthanum carbonate (F = 5.96, P = 0.02) and CAC score (F = 4.47, P = 0.03, Table 1). Receiver operating characteristic curve showed SOx = 269.5 µmol/L was the best cut-off for predicting CVD events. We divided subjects into two groups by this cut-off SOx value and revealed SOx was associated with new-onset CVD events (N = 60, P = 0.01) even after adjusted by age under 75 years (N = 52, P = 0.03) or both age under 75 years and CAC score under 1000 (N = 28, P = 0.04) by the Kaplan–Meier method (Fig. 1). CONCLUSION SOx was associated with CAC score, lanthanum carbonate and CVD events in ESRD patients undergoing haemodialysis.

Phosphate restriction using a processed clay mineral reduces vascular pathologies and microalbuminuria in rats with chronic renal failure

BackgroundThe progression of chronic kidney disease (CKD) is associated with an increasing risk of cardiovascular morbidity and mortality due to elevated serum phosphate levels. Besides low phosphate diets and hemodialysis, oral phosphate binders are prescribed to treat hyperphosphatemia in CKD patients. This study reports on a processed clay mineral as a novel and efficient phosphate sorbent with comparable efficacy of a clinically approved phosphate binder.Methods5/6 nephrectomized rats, which develop chronic renal failure (CRF), received a high phosphate and calcium diet supplemented with either a processed Montmorillonite-Illite clay mineral (pClM) or lanthanum carbonate (LaC) for 12 weeks. Levels of plasma uremic toxins, glomerular filtration rates and microalbuminuria were determined and the histomorphology of blood vessels and smooth muscle cells was analyzed.Results5/6 nephrectomy induced an increase in plasma uremic toxins levels and progressive proteinuria. Treatment of CRF rats with pClM decreased observed vascular pathologies such as vascular fibrosis, especially in coronary vessels. The transition of vascular smooth muscle cells from a contractile to a secretory phenotype was delayed. Moreover, pClM administration resulted in decreased blood creatinine and urea levels, and increased glomerular filtration rates, reduced microalbuminuria and eventually the mortality rate in CRF rats.ConclusionOur study reveals pClM as a potent phosphate binding agent with beneficial impacts on pathophysiological processes in an animal model of CKD. pClM effectively attenuates the progression of vascular damage and loss of renal function which are the most severe consequences of chronic renal failure.

Adsorption of Phosphate by Surface Precipitation on Lanthanum Carbonate Through In Situ Anion Substitution Reactions

Graphical Abstract

La/Al engineered bentonite composite for efficient phosphate separation from aqueous media: Preparation optimization, adsorptive behavior and mechanism insight

Herein, lanthanum/aluminum engineered bentonite (LAB) was developed for efficient phosphate separation from aqueous media. LAB-1 (La/Al = 1) exhibited highest adsorption capacity among all samples, and batch experiments indicated that LAB-1 could maintain efficient phosphate uptake (＞ 90%) within the interference of competing anions (Cl−, NO3–, HCO3– and SO42−). Acidic condition (pH 3–6) was beneficial to phosphate capturing, and the maximum experimental capacity of LAB-1 was detected as ∼ 93.61 mg P/g. Kinetic modelling with the preferred fitness of pseudo-second-order model revealed the chemisorption nature of phosphate uptake process, while isotherm test suggested multilayer adsorption of phosphate on heterogeneous LAB-1 surface. Adsorption thermodynamics uncovered the spontaneous and endothermic feature of phosphate loading on LAB-1, and phosphate loading contributed to increased randomness of engineered surface. Characterization analysis demonstrated the growth of crystalline lanthanum carbonate hydrate on LAB-1, while phosphate uptake converted it to LaPO4·0.5H2O crystal. However, amorphous Al hydroxide and Al-P complex after adsorption were supposed. Detailed investigation demonstrated the joint involvement of La and Al sites and the formation of metal-P complex through ligand exchange.

An open-label phase 2 trial to assess the efficacy, safety and pharmacokinetics of lanthanum carbonate in hyperphosphatemic children and adolescents with chronic kidney disease undergoing dialysis

BackgroundThis study assessed the efficacy, tolerability and pharmacokinetics (PK) of lanthanum carbonate (LC) in hyperphosphatemic children and adolescents with chronic kidney disease (CKD) undergoing dialysis.MethodsThis was a three-part, multicenter, open-label study of LC (oral powder formulation) in patients 10 to < 18 years old with CKD undergoing dialysis. In part 1, the single-dose PK of LC (500 mg, ≤12 years old; 1000 mg, > 12 years old) were summarized. In part 2, patients received calcium carbonate (CC [chewable tablet formulation]) (1500–6500 mg [total daily dose]) followed by LC (powder formulation) (1500–3000 mg [total daily dose]), or LC only (1500–3000 mg [total daily dose]), each for 8 weeks. During part 3, patients received LC (1500–3000 mg [total daily dose]) for up to 6 months. The primary efficacy endpoint was the proportion of LC-treated patients achieving serum phosphorus control after 8 weeks during parts 2 and/or 3, defined as: ≤1.94 mmol/L, < 12 years old; ≤1.78 mmol/L, ≥12 years old. Secondary efficacy endpoints included: the proportion of patients who achieved serum phosphorus control after 8 weeks of treatment with CC followed by 8 weeks of treatment with LC (with a washout period between treatments). The safety of LC and CC was also evaluated.ResultsIn part 1, 20 patients received a single dose of LC. In part 2, 53 and 51 patients were treated with CC and LC for 8 weeks, respectively. During part 3, 42 patients received LC for up to 6 months. Most patients were white and male. For the primary efficacy endpoint, 50% (17/34) of patients who received LC for 8 weeks during parts 2 and/or 3 achieved serum phosphorus control. After 8 weeks of treatment with CC, 58.8% of patients achieved serum phosphorus control; after a subsequent washout period and 8 weeks of treatment with LC, 70.6% of patients achieved serum phosphorus control. Tmax and t1/2 occurred within 3–8 h and ~ 19 h, respectively; however, variability was observed. LC and CC were generally well tolerated.ConclusionsThese data support the use of LC to manage hyperphosphatemia in pediatric patients with CKD undergoing dialysis.Trial registrationClinicalTrials.gov identifier: NCT01696279; EudraCT identifier: 2012–000171-17.Date of registration: 01/10/2012.

Lanthanum Carbonate Opacities-A Systematic Review.

Background: Lanthanum carbonate is a phosphate binder used in advanced kidney disease. Its radiopaque appearance has been described in many case studies and case series. Misinterpretation of this phenomenon leads to unnecessary diagnostic tests and procedures. The objectives of this study were to summarize the literature on lanthanum carbonate opacities and present a visual overview. Methods: A systematic search was conducted using MEDLINE, Embase, and Web of Science. We included all types of studies, including case reports/studies, describing radiological findings of lanthanum carbonate opacities in patients with chronic kidney disease. No filter for time was set. Results: A total of 36 articles were eligible for data extraction, and 33 articles were included in the narrative synthesis. Lanthanum carbonate opacities were most commonly reported in the intestines (26 studies, 73%), stomach (8 studies, 21%), and the aerodigestive tract (2 studies, 6%). The opacities in the intestine were most frequently described as multiple, scattered radiopaque densities, compared with the aerodigestive tract, where the opacities were described as a single, round foreign body. Suspicion of contrast medium or foreign bodies was the most common differential diagnosis. LC opacities in patients with CKD are commonly misinterpreted as foreign bodies or suspect contrast media. Conclusions: CKD patients treated with LC may have opacities throughout the digestive tract that can vary in appearance. Stopping LC treatment or changing to an alternative phosphate binder prior to planned image studies can avoid diagnostic confusion. If this is not an option, knowledge of the presentation of LC opacities is important.

Lanthanum carbonate grafted ZSM-5 for superior phosphate uptake: Investigation of the growth and adsorption mechanism

• Synthesis of LC-ZSM-5 is optimized to achieve high adsorption capacity. • Agglomeration will occur as synthesis time of LC-ZSM-5 increases. • Thermodynamic study indicates a spontaneously physicochemical adsorption. • Adsorption mechanism includes electrostatic attraction and ligand exchange. • Adsorption capacity of LC-ZSM-5 maintains near 70% after 5 cycling runs. High-efficiency phosphate removal from wastewater is crucial for protecting environmental stability. In this work, a lanthanum carbonate grafted ZSM-5 adsorbent (LC-ZSM-5) was prepared and optimized by a Box-Behnken design. The higher temperature, molar ratio of urea to lanthanum and initial lanthanum concentration are beneficial for LC-ZSM-5 synthesis, and the adsorption capacity of LC-ZSM-5 under optimistic conditions was 91.2 mg-PO 4 3- /g. The growth mechanism indicates that the LC particles grow larger with synthesis time and finally agglomerate, and 12 h is the best synthesis time. The thermodynamic results show that phosphate adsorption over LC-ZSM-5 is a spontaneously exothermic and combined physicochemical adsorption process. Kinetic studies suggest that higher temperatures help increase the phosphate adsorption rate, and chemical adsorption plays an important role during adsorption with an activation energy E a of 42.7 kJ/mol. The adsorption mechanism of the phosphate uptake process includes electrostatic attraction and ligand exchange, through which LC is changed to lanthanum phosphate (LP) during adsorption. Finally, the regeneration study revealed that LC-ZSM-5 still exhibited a high adsorption capacity after 5 cycles, showing its satisfactory regeneration ability and potential industrial application.