Synthesis and biological evaluation of <Superscript>99m</Superscript>Tc labeled aryl piperazine derivatives as cerebral radiotracers

The aim of this study is to develop cerebral radiotracers for central nervous system receptors imaging. The synthesis, characterization and biological evaluation of two aryl piperazine ^99mTc-radiocomplexes based on the piano stool motif [CpM(CO₃)] (Cp = cyclopentadienyl, M = ^99mTc/Re) is reported. The ^99mTc-radiocomplexes were obtained quickly (time < 5 min) with high radiochemical yields. The ^99mTc-radiocomplexes characterized by high performance liquid chromatography comparison with the rhenium surrogates have both a suitable lipophilicity and are able to cross the blood brain barrier with 0.43 ± 0.05 and 1.96 ± 0.06% ID/g of brain uptake, at 10 min post injection.     

Zirconium silicotungstate matrix as a prospective sorbent material for the preparation of <Superscript>113</Superscript>Sn/<Superscript>113m</Superscript>In generator

The zirconium silicotungstate (ZrSiW) was studied as an effective sorbent material to be used in the ¹¹³Sn/^113mIn generator. The results elucidated that the distribution coefficient of ¹¹³Sn (3700 mL/g) is greater than ^113mIn (275 mL/g) from 0.1 M HCl acid solution to the ZrSiW material. The maximum sorption capacity of Sn (IV) was found to be 33 mg per gram ZrSiW (~?0.3 mmol/g). The elution yield of ^113mIn was found to be >?78?±?6.4% with an acceptable purity of radionuclidic and radiochemical (≥?99.99 and 96.8%, respectively). The rigorous separation of ^113mIn from the ¹²⁵Sb was carried out due to its long half-life (2.758 years) and beta emission that causes tissue damage. Zr, W and Si levels are below the permitted limit in the ^113mIn eluate.     

Synthesis and biological evaluation of fatty acid derivatives for myocardial imaging containing [<Superscript>99m</Superscript>Tc(CO)<Subscript>3</Subscript>]<Superscript>+</Superscript>

Radiolabeled fatty acids as myocardial metabolic agent are used for detecting ischemic heart disease, however, no ^99mTc-labeled fatty acids have potential use in clinical diagnosis. In this work, five fatty acid analogues labeled with ^99mTc were firstly synthesized and characterized, their biological behaviors were investigated. All Radiotracers had good stability when incubated in rat serum for 3 h at 37 °C. ^99mTc -CpT-12-ODPPA (8b) showed higher initial myocardial uptake (8.17% ID/g at 1 min postinjection) and good heart/blood ratio (2.58 at 30 min postinjection). ^99mTc-11-dpa-OUFA (2b) as positively charged lipophilic compounds had reasonable heart uptake (5.59% ID/g at 1 min postinjection) and good retention (1.89% ID/g at 60 min postinjection). Unfortunately, no great improvement was obtained by the five ^99mTc-labeled fatty acid analogues for the short myocardial retention and poor heart/liver ratios.     

Synthesis,bioevaluation and gamma scintigraphy of <Superscript>99m</Superscript>Tc-N-2-(furylmethyl iminodiacetic acid) complex as a new renal radiopharmaceutical

A ligand of N-2-(furylmethyl iminodiacetic acid) (FMIDA) has been easily labeled by a tetradentate chelating agent of [^99mTc]. Factors like a stannous chloride solution as a reducing agent (100 μg), substrate amount (100 μg), pH (7), in vitro stability (8 h) and temperature (37 °C) have been systematically studied to optimize high radiochemical yield (98.0%). The radiochemical conversion was calculated on thin-layer chromatography, paper electrophoresis, and high performance liquid chromatography. Biodistribution study showed that this complex was removed from the kidneys and bladder path way during 1 h post injection. Therefore, [^99mTc]FMIDA may be used as renal function radiotracer.     

Synthesis of [64Cu]DOTA-ADIBON3-Ala-PEG28-A20FMDV2 via copper-free click chemistry for PET imaging of integrin αvβ6

Catalyst-free click reactions are effective chemical tools for synthesis of radiometal-based radiopharmaceuticals offering advantages towards preparation of non-toxic agents with high specific activity. In the present study the radiotracer [⁶⁴Cu]DOTA-ADIBON₃-Ala-PEG₂₈-A20FMDV2, [⁶⁴Cu]3, was synthesized for positron emission tomography imaging of integrin α_vβ₆ expressing tumors via a strain-promoted click reaction using both a “pre-click” and “post-click” approaches. The radiotracer, prepared in >99 % radiochemical yield, was evaluated in vitro (64.6 ± 2.8 % binding to α_vβ₆-positive cells vs. <5 % to α_vβ₆-negative cells) and in vivo (α_vβ₆-positive tumor uptake: 1.52 ± 0.16 % ID/g, 24 h p.i.). While the high initial renal uptake (76.2 ± 10.7 % ID/g at 1 h p.i.) was comparable to a previously reported radiotracer, [⁶⁴Cu]DOTA-PEG₂₈-A20FMDV2, [⁶⁴Cu]3 showed notably improved renal clearance (11.3 ± 2.5 % ID/g at 24 h p.i.). Thus, the introduction of a chelator-strained alkyne system resulted in improved pharmacokinetics for the present radiotracer, highlighting the attractive prospects of strain-promoted click-based preparations in the construction of radiometalated bioconjugates for targeted molecular imaging and therapy.     

99mTc-nebivolol as a novel heart imaging radiopharmaceutical for myocardial infarction assessment

Non-invasive quantification of myocardial β-receptors could become an independent prognostic marker for chronic heart failure and cardiovascular disorders. The aim of this study was to formulate a novel radiopharmaceutical for the detection of myocardial infarction at early stages in susceptible patients, which requires the development of high myocardium affinity radiopharmaceuticals able to establish an accurate in vivo quantification of cardiac β₁-adrenoceptors. This was attained by the direct complexation of nebivolol as a cardioselective agent with technetium-99m as one of the most useful radionuclides in diagnostic nuclear medicine. Factors affecting the radiochemical yield such as nebivolol amount, stannous chloride amount, reaction time and pH of the reaction mixture were optimized. The results showed that the radiochemical yield was 95 ± 2.87 % and the radiolabeled compound was separated by high performance liquid chromatography. In vitro studies showed that the formed complex was stable for up to 24 h. In vivo uptake of ^99mTc-nebivolol in the heart was 4.55 ± 0.23 % ID/g organ at 0.5 h post injection, whereas the clearance from Albino mice appeared to proceed via the hepatobiliary and renal clearance pathways. Predosing mice with cold nebivolol reduced the heart uptake to 1.1 ± 0.02 % and further confirmed the high specificity and selectivity of this radiotracer for the assessment of the myocardial β₁-adrenoceptors.     

Bioaccumulation of <Superscript>137</Superscript>Cs and <Superscript>60</Superscript>Co by bacteria isolated from spent nuclear fuel pools

This paper is focused on a characterization of bacterial contamination in pool water of the interim spent fuel storage (JAVYS Inc.) in Slovak Republic and on bioaccumulation of ¹³⁷Cs and ⁶⁰Co by isolated bacteria. Bacterial community in pool water is kept on very low level by extremely low concentration of solutes in deionized water and by the efficient water filtration system. Based on standard methods and sequencing of 16S rDNA four pure bacterial cultures were identified as Kocuria palustris, Micrococcus luteus, Ochrobactrum spp. and Pseudomonas aeruginosa. Isolated aerobic bacteria were able to bioaccumulate ¹³⁷Cs and ⁶⁰Co in laboratory experiments. The mechanism of Co and Cs binding involve rapid interactions with anionic groups of the components of cell surface and in the case of Cs⁺ ions is followed by transport processes across cytoplasm membranes and by intracellular distribution. The maximum specific uptake of Cs⁺ after 48 h cultivation in mineral medium (MM) reached 7.54 ± 0.48 μmol g^?1 dw (Ochrobactrum spp.), 19.6 ± 0.1 μmol g^?1 dw (M. luteus) and 20.1 ± 2.2 μmol g^?1 dw (K. palustris). The maximum specific uptake of Co²⁺ after 24 h cultivation in MM reached 31.1 ± 3.5 μmol g^?1 dw (Ochrobactrum spp.), 86.6 ± 12.2 μmol g^?1 dw (M. luteus) and 16.9 ± 1.2 μmol g^?1 dw (K. palustris). These results suggest that due to the long lasting uptake of ¹³⁷Cs, ⁶⁰Co and other radionuclides by biofilm in pool water high specific radioactivities (Bq m^?2) can be expected on stainless steel walls of pools.     

Synthesis and evaluation of a new bombesin analog labeled with <Superscript>99m</Superscript>Tc as a GRP receptor imaging agent

Tumors such as prostate, small cell lung cancer, breast, gastric and colon cancer are known to overexpress receptors to bombesin (BBN). In this study, a new bombesin analogue was labeled with ^99mTc via HYNIC and tricine/EDDA as coligands and investigated further. HYNIC-GABA-Bombesin (7–14) NH₂ was synthesized using a standard Fmoc strategy. Labeling with ^99mTc was performed at 100 °C for 10 min and radiochemical analysis involved ITLC and HPLC methods. The stability of radiopeptide was checked in the presence of humane serum at 37 °C up to 24 h. The receptor bound internalization and externalization rates were studied in GRP receptor expressing PC-3 cells. Biodistribution of radiopeptide was studied in nude mice bearing PC-3 tumor. Labeling yield of >98% was obtained corresponding to a specific activity of ~2.6 MBq/nmol. Peptide conjugate showed good stability in the presence of human serum. The radioligand showed high and specific internalization into PC-3 cells (14.63 ± 0.41% at 4 h). In biodistribution studies, a receptor-specific uptake was observed in GRP-receptor-positive organs so that after 4 h the uptakes in mouse tumor and pancreas were 1.31 ± 0.18 and 1.2 ± 0.13% ID/g, respectively.     

<Superscript>99</Superscript>Mo/<Superscript>99m</Superscript>Tc generators based on aluminum molybdate gel matrix prepared by nano method

A procedure for preparation of ⁹⁹Mo/^99mTc radioisotope generator based on low specific activity neutron activated ⁹⁹Mo was developed. Aluminum molybdate(VI)-⁹⁹Mo of high Mo(VI) content (~?364 mg/g Al⁹⁹Mo) was prepared by mixing low specific activity molybdate(VI)-⁹⁹Mo and aluminum mixture solution with isoamyl alcohol. Al⁹⁹Mo gel matrix was precipitated when the pH of the mixture solution was raised to ~?5 by addition of NaOH to the mixture. Radiometric measurements indicate the strong fixation of Molybdate(VI)-⁹⁹Mo species in the form of the sparingly insoluble Al⁹⁹Mo gel matrix. The prepared AlMo gel matrix was physiochemically characterized. Al⁹⁹Mo gel matrix was used as a base material for preparation of ⁹⁹Mo/^99mTc generator. The ^99mTc eluted from ⁹⁹Mo/^99mTc radioisotope generator was found to have relatively high elution yield (84?±?2.3%), radionuclidic (≥?99.99%), radiochemical (98.1?±?0.9%) and chemical purity.     

Radiosynthesis and Biodistribution of <Superscript>99m</Superscript>Tc-Metronidazole as an <Emphasis Type="Italic">Escherichia coli</Emphasis> Infection Imaging Radiopharmaceutical

Bacterial infection poses life-threatening challenge to humanity and stimulates to the researchers for developing better diagnostic and therapeutic agents complying with existing theranostic techniques. Nuclear medicine technique helps to visualize hard-to-diagnose deep-seated bacterial infections using radionuclide-labeled tracer agents. Metronidazole is an antiprotozoal antibiotic that serves as a preeminent anaerobic chemotherapeutic agent. The aim of this study was to develop technetium-99m-labeled metronidazole radiotracer for the detection of deep-seated bacterial infections. Radiosynthesis of ^99mTc-metronidazole was carried by reacting reduced technetium-99m and metronidazole at neutral pH for 30 min. The stannous chloride dihydrate was used as the reducing agent. At optimum radiolabeling conditions, ~ 94% radiochemical was obtained. Quality control analysis was carried out with a chromatographic paper and instant thin-layer chromatographic analysis. The biodistribution study of radiochemical was performed using Escherichia coli bacterial infection-induced rat model. The scintigraphic study was performed using E. coli bacterial infection-induced rabbit model. The results showed promising accumulation at the site of infection and its rapid clearance from the body. The tracer showed target-to-non-target ratio 5.57 ± 0.04 at 1 h post-injection. The results showed that ^99mTc-MNZ has promising potential to accumulate at E. coli bacterial infection that can be used for E. coli infection imaging.     

Isolation of quercetin and mandelic acid from <Emphasis Type="Italic">Aesculus indica</Emphasis> fruit and their biological activities

Background

In this study Aesculus indica fruit was subjected to isolation of phytochemicals. Two antioxidants quercetin and Mandelic acid were isolated in pure state. The free radical scavenging and acetyl choline esterase inhibitory potential of the crude extract and sub fractions were also determined.

Results

The antioxidant capacity of crude extract, fractions and isolated compounds were determined by DPPH and ABTS methods. Folin-Ciocalteu reagent method was used to estimate the total phenolic contents and were found to be 78.34?±?0.96, 44.16?±?1.05, 65.45?±?1.29, 37.85?±?1.44 and 50.23?±?2.431 (mg/g of gallic acid) in crude extract, ethyl acetate, chloroform, n-hexane and aqueous fractions respectively. The flavonoid concentration in crude extract, ethyl acetate, chloroform, n-hexane and aqueous fraction were; 85.30?±?1.20, 53.80?±?1.07, 77.50?±?1.12, 26.30?±?1.35 and 37.78?±?1.25 (mg/g of quercetin) respectively. The chloroform fraction was more potent against enzymes, acetyl choline esterase and butyryl choline esterase (IC₅₀?=?85 and 160 μg/ml respectively). The phenolic compounds in the crude extract and fractions were determined using HPLC standard method. Chlorogenic acid, quercetin, phloroglucinol, rutin, mandelic acid and hydroxy benzoic acid were detected at retention times 6.005, 10.062, 22.623, 30.597, 35.490 and 36.211 in crude extract and different fractions. The ethyl acetate fraction was rich in the targeted compounds and was therefore subjected to column isolation. The HPLC chromatogram of isolated compounds showed single peak at specified retention times which confirms their isolation in pure state. The isolated compounds were then characterized by FTIR and NMR spectrophotometric techniques.

Conclusion

The Aesculus indica fruit extracts showed antioxidant and anticholine esterase inhibitory potentials. Two bioactive compounds were isolated in the pure form ethyl acetate fraction. From results it was concluded that the fruit of this plant could be used to minimize oxidative stress caused by reactive oxygen species.

     

Preparation of <Superscript>166</Superscript>Dy/<Superscript>166</Superscript>Ho-chitosan as an in vivo generator for radiosynovectomy

¹⁶⁶Ho is one of the most effective radionuclides used for radiosynovectomy. One method to deliver this radioisotope to target tissue is via the ¹⁶⁶Dy/¹⁶⁶Ho in vivo generator system. The aim of this work was to prepare ¹⁶⁶Dy/¹⁶⁶Ho-chitosan (¹⁶⁶Dy/¹⁶⁶Ho-CHIT) in vivo generator for radiosynovectomy applications. ¹⁶⁶Dy obtained by the irradiation of natural ¹⁶⁴Dy target. ¹⁶⁶Dy was separated from ¹⁶⁶Ho by extraction chromatographic method (separation yield; 93% and separation factor;1.7). Chitosan labeling was performed in acetic acid with 99.3 ± 0.6% radiochemical purity. Biodistribution studies on intraarticular injected rats demonstrated high retention in the knee joint even 7 days showing no radioactivity leakage from the injection site into other organs as well as any translocation of the daughter nucleus after β^? decay of ¹⁶⁶Dy.     

Development of <Superscript>111</Superscript>In labeled insulin for receptor imaging/therapy

In order to target insulin receptors in various diabetic and insulinoma conditions, human recombinant insulin was successively labeled with [¹¹¹In]-indium chloride after conjugation with freshly prepared cyclic DTPA-dianhydride (ccDTPA). The best results of the conjugation were obtained by addition of 0.5 mL of an insulin pharmaceutical solution (5 mg/mL, in phosphate buffer, pH 8) to a glass tube pre-coated with DTPA-dianhydride (0.01 mg) at 25 °C with continuous mild stirring for 30 minutes. Radio-thin layer chromatography (RTLC), instant thin layer chromatography (ITLC) and high performance liquid chromatography (HPLC) have shown an overall radiochemical purity of higher than 93% at optimized conditions (specific activity = 550–750 MBq/mg, radiochemical yield =81%). The white blood cell labeling capacity of the tracer was determined up to 4 hours at 37 °C. Preliminary in vivo studies in normal rat model was performed to determine the biodistribution of the radiotracer up to 48 hours. It showed a high liver and spleen uptake of the tracer which is consistent with other reported radiolabeled insulins. SPECT images have also shown high liver accumulation of the tracer.     

Preparation and preliminary evaluation of <Superscript>211</Superscript>At-labeled amidobisphophonates

In this paper, 3-amino-1-hydroxypropylidene-1,1-bisphosphonate(APB), a amidobisphophonate was synthesized and labeled with the α-emitter ²¹¹At by an indirect method using N-succinimidyl 5-(tributylstannyl)-3-pyridinecarboxylate (SPC) as a bi-functional linker, and the conjugated amidobisphophonate (²¹¹At-SAPC-APB) was preliminarily evaluated in vitro and in vivo by comparison with free astatide (²¹¹At⁻) and ^99mTc-MDP. 3-amino-1-hydroxypropylidene-1,1-bisphosphonate(APB) was prepared using β-alanine as the starting material. With SPC bi-functional linker, APB was conjugated with ²¹¹At in a labeling yield of 80–90% with radiochemical purity of more than 99%. The conjugated amidobisphophonate (²¹¹At-SAPC-APB) exhibited considerable stability in vitro, in that the radiochemical purity of ²¹¹At-SAPC-APB was still more than 98% in 0.1 mol/L PBS (pH 7.6) or in fetal calf serum, even stayed for 24 h at room temperature (RT). Biodistribution of ²¹¹At-SAPC-APB was investigated in NIH strain mice by I.V injection. The results showed that ²¹¹At-SAPC-APB could rapidly locate in shank, with the maximum uptake of 23.70 ± 2.29% I.D/g at 6 h, earlier than that of ^99mTc-MDP at 12 h, and stayed in the bone for long time. Moreover, ²¹¹At-SAPC-APB uptake in some key organs or tissues, especially in thyriod, stomach, lung and spleen, was much less than that of free astatide (²¹¹At⁻), implying that ²¹¹At-SAPC-APB was constantly stable in vivo as well as in vitro. These results indicated that ²¹¹At-SAPC-APB will be a suitable candidate for the targeted radiotherapy of bone metastases and should be further investigated.     

Evaluation of a new radiolabeled bombesin derivative with 99mTc as potential targeted tumor imaging agent

Gastrin-releasing peptide (GRP) receptors are over-expressed in various human tumor including breast and prostate which can be targeted with bombesin for diagnosis and targeted therapy. High abdominal accumulation and the poor in vivo stability of radiolabeled bombesin analogues may represent a limitation for diagnostic imaging and targeted therapy. In this study a new bombesin derivative was labeled with ^99mTc via HYNIC and tricine as a coligand and investigated further. The peptide HYNIC conjugate was synthesized on a solid phase using Fmoc strategy. Labeling with ^99mTc was performed at 100 °C for 10 min and radiochemical analysis involved ITLC and HPLC methods. The stability of radiopeptide was checked in the presence of human serum at 37 °C up to 24 h. Internalization was studied with the human GRP receptor cell line PC-3. The Biodistribution was studied in mice. Labeling yield of >98 % was obtained to correspond a specific activity of ~80.9 GBq/μmol. Radioconjugate internalization into PC-3 cells was high and specific (15.6 ± 1.9 % at 4 h). A high and specific uptake in GRP-receptor-positive organs such as mouse tumor and pancreas (2.11 ± 0.18 and 1.78 ± 0.09 % ID/g after 1 h respectively) was also determined.     

Preparation and preliminary evaluation of [<Superscript>67</Superscript>Ga]-tetra phenyl porphyrin complexes as possible imaging agents

[⁶⁷Ga]labeled tetraphenyl porphyrin ([⁶⁷Ga]-TPP) was prepared using freshly prepared [⁶⁷Ga]GaCl₃ and tetraphenyl porphyrin (TPPH₂) for 30–60 min at 25 °C (radiochemical purity: >97 ± 1% ITLC, >98 ± 0.5% HPLC, specific activity: 13–14 GBq/mmol). Stability of the complex was checked in final formulation and human serum for 24 h. The partition coefficient was calculated for the compound (log P 1.89). The biodistribution of the labeled compound in vital organs of wild-type rats was studied using scarification studies and SPECT imaging up to 24 h. A detailed comparative pharmacokinetic study performed for ⁶⁷Ga cation and [⁶⁷Ga]-TPP. The complex is mostly washed out from the circulation through kidneys and can be an interesting tumor imaging/targeting agent due to low liver uptake and rapid excretion through the urinary tract.     

Radio labeling,quality control and biodistribution of <Superscript>99m</Superscript>Tc-cefotaxime as an infection imaging agent

Cefotaxime, a cephalosporin antibiotic, used to treat bacterial infections was investigated to label with ^99mTc. Labeling was performed using sodium dithionite as a reducing agent at 100 °C for 10 min and radiochemical analysis involved ITLC and HPLC methods. The stability of labeled antibiotic was checked in the presence of human serum at 37 °C up to 24 h. The maximum radiolabeling yield was 92 ± 2%. Bacterial binding assay was performed with S. aureus and the in vivo distribution was studied in mice. Images showed minimal accumulation in non-target tissues, with an average target/non-target ratio of 2.89 ± 0.58.     

Experimental and FLUKA study relevant to the production of <Superscript>124</Superscript>I through <Superscript>nat</Superscript>Te(p,xn) reaction at a medium-sized cyclotron

A radiochemical methodology for the determination of ⁹⁴Nb in low-level radioactive wastes from nuclear power plant was proposed. Although ⁹⁴Nb is a strong gamma emitter, its concentration in radioactive waste samples is usually several orders of magnitude lower than that of other β–γ emitters, whose emissions interferes in the detection of the emission lines of ⁹⁴Nb. The procedure involves acid digestion, precipitation, cation exchange chromatography by using Amberlite IRA120 resin, extraction chromatography by using TEVA resin to isolate the Nb and the gamma spectrometry to its measurement. The chemical yield was 70% in average. Samples of evaporator concentrate and spent resin were analyzed. For the samples of the evaporator concentrate, the results obtained were below L _D = 9.59 × 10^?4 Bq g^?1. For the spent resin an average result of 1.54 × 10² Bq g^?1 was obtained.     

Development of <Superscript>177</Superscript>Lu-DOTA-anti-CD20 for radioimmunotherapy

Rituximab was successively labeled with ¹⁷⁷Lu-lutetium chloride. ¹⁷⁷Lu chloride was obtained by thermal neutron flux (4 × 10¹³ n cm⁻² s⁻¹) of natural Lu₂O₃ sample with a specific activity of 2.6–3 GBq/mg. The macrocyclic bifunctional chelating agent, N-succinimidyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA-NHS) was prepared at 25 °C using DOTA, N-hydroxy succinimide (NHS) in CH₂Cl₂. DOTA-rituximab was obtained by the addition of 1 mL of a rituximab pharmaceutical solution (5 mg/mL, in phosphate buffer, pH 7.8) to a glass tube pre-coated with DOTA-NHS (0.01–0.1 mg) at 25 °C with continuous mild stirring for 15 h. Radiolabeling was performed at 37 °C in 24 h. Radio-thin layer chromatography showed an overall radiochemical purity of >98% at optimized conditions (specific activity = 444 MBq/mg, labeling efficacy; 82%). The final isotonic ¹⁷⁷Lu-DOTA-rituximab complex was checked by gel electrophoresis for structure integrity control. Radio-TLC was performed to ensure that only one species was present after filtration through a 0.22 μm filter. Preliminary biodistribution studies in normal rats were carried out to determine complex distribution of the radioimmunoconjugate up to 168 h. The biodistribution data were in accordance with other antiCD20 radioimmunoconjugates already reported.     

Hydrolytic Behavior of La<Superscript>3+</Superscript> and Sm<Superscript>3+</Superscript> at Various Temperatures

The hydrolytic species of lanthanide ions, La³⁺ and Sm³⁺, in water at I = 0.1 mol·dm^?3 KCl ionic strength and temperatures of 298.15, 310.15 and 318.15 K were investigated by potentiometry. The hydrolytic species were modeled by the HySS simulation program. From the results, the hydrolytic species of each metal ion at different temperatures were calculated using the program HYPERQUAD2013. The hydrolysis constants (log₁₀ β) of [La(OH)]²⁺ and La(OH)₃ were calculated as ?8.52 ± 0.46, ?26.84 ± 0.48, and log₁₀ β values of [Sm(OH)]²⁺, [Sm(OH)₂]⁺, Sm(OH)₃ were calculated as ?7.11 ± 0.21, ?15.84 ± 0.25 and ?23.44 ± 0.52 in aqueous media at 298.15 K, respectively. The dependence of the hydrolysis constants on the temperature allowed us to calculate the enthalpy, entropy, and Gibbs energy of hydrolysis values of each species.