Production of pharmaceutical grade [201Tl]Thallous chloride using 30 MeV cyclotron.

Multiple patient doses of [201Tl]TlCl has been produced using electrodeposited enriched 203Tl in 30 MeV cyclotron (Cyclone-30) with 28 MeV proton energy at 50 µA beam current for 8 h. Ion Exchange Column Chromatography (IECC) and liquid-liquid extraction has been employed for semi-automated radiochemical separation and purification of produced [201Tl]TlCl. The produced [201Tl]TlCl was used in coronary artery disease (CAD) patients.

Preparation of [68Ga]Ga-Chloride from 68Zn solid target for the synthesis of pharmaceutical grade [68Ga]Ga-PSMA-11 and [68Ga]Ga-DOTA-TATE.

68Ga is produced from enriched zinc-68 target electrodeposited on copper base material which was irradiated with 15 MeV proton energy in 30 MeV cyclotron. A modified semi-automated separation and purification module was used to obtain pharmaceutical grade [68Ga]GaCl3 in 35 ± 5 min. The quality of [68Ga]GaCl3 produced was in accordance with Pharmeuropa 30.4. The [68Ga]GaCl3 was utilized for the formulation of multiple doses of [68Ga]Ga-PSMA-11 and [68Ga]Ga-DOTATATE. The quality of [68Ga]Ga-PSMA-11 and [68Ga]Ga-DOTATATE were also in accordance with Pharmacopeia.

Clinical doses production of pharmaceutical grade Sodium[18F]Fluoride using modified integrated fluidic processor in a SYNTHERA® module.

A fully automated large-scale production of sodium [18F]fluoride ([18F]NaF) using SYNTHERA module with a modification in integrated fluidic processor (IFP) is reported. This modified IFP module is used to prepare [18F]NaF with more than 98% non-decay corrected radiochemical yield (RCY) within 5 min with specifications in accordance with United State Pharmacopeia (USP) monograph. The graphical user interface (GUI) is designed to perform the synthesis steps either manually or automatically and give information to the operator during the course of production. The desired clinical results add support to indigenously produced [18F]NaF as a pharmaceutical grade diagnostic radiopharmaceutical.

Clinical Efficacy of Sodium [99mTc] Pertechnetate from Low Specific Activity 99Mo/99mTc Autosolex Generator in Hospital Radiopharmacy Centre.

BACKGROUND: Few nuclear reactors in the world producing high specific activity (HSA) 99Mo using enriched 235U (HEU), are aging and are planned for shut down in the near future. Further, HEU will not be freely available, due to safeguards, and the technology for 99Mo from low-enriched 235U (LEU) is not yet widely accepted since 239Pu contamination in the product is an issue. Production of 99mTc from low specific activity (LSA) 99Mo obtained from 98Mo(n,)99Mo reaction in research reactor and 100Mo(,n)99Mo reaction in accelerator or directly from 100Mo(p,2n)99mTc nuclear reaction in cyclotron, has been explored [1]. The methyl ethyl ketone (MEK) based solvent extraction technique is n well known method for the separation of 99mTc from low specific activity 99Mo. The 99Mo/99mTc autosolex generator [2], a computer controlled automated module, utilizes the conventional MEK solvent extraction method for extraction of 99mTc. Herein, we have validated the usage of autosolex for preparation of pharmacopoeia grade 99mTcO4- from 7.40-27.5 GBq of LSA 99Mo-SodiumMolybdate (99MoO42-) solution and validated the quality of the 99mTcO4- by preparing wide range of 99mTc-radiopharmaceuticals (99mTc-RP). MATERIALS AND METHODS: The 99mTcO4- was extracted from the autosolex as described in [2] starting from 7.40-27.5 GBq of LSA 99MoO42- and subjected to the required physico-chemical and biological quality control (QC) tests. The eluted 99mTcO4- labeled various fourth generation 99mTc radiopharmaceuticals cold kits (99mTc-cold kits) apart from regular 99mTc-cold kits in our centre. Various 99mTc-RP extracted 99mTcO4- using standard procedures [3] were prepared and subjected to required QC as Indian Pharmacopeia monograph [4] and used in scintigraphic imaging in patients. The radiation exposure dose to the operator were compared between autosolex and manual MEK based solvent extraction generator. RESULTS: The extracted 99mTcO4- from autosolex is a clear and colorless solution with pH between 5.0-6.5. The elemental molybdenum (Mo) and aluminum (Al) content <10µg/mL, MEK levels <0.1%, 99Mo breakthrough <0.030% and radiochemical purity (RCP) >98%. All the extracted 99mTcO4- batches complies sterility test, endotoxin limit (EL) <5EU/mL. The RCP of all the labeled 99mTc-RP >95%. The autosolex delivers much less radiation dose to the operator than the convention manually handled MEK based solvent extraction generator. CONCLUSIONS: Autosolex Generator was successfully used to obtain pharmaceutical grade 99mTcO4- from LSA 99MoO42- and generator is safe in radiological and pharmacological point of view. The suitability of the autosolex for use in hospital radiopharmacy was shown by using the 99mTcO4- to prepare various 99mTc-RP and using these 99mTc-RP for scintigraphic imaging in patients.

A peptide-modified solid lipid nanoparticle formulation of paclitaxel modulates immunity and outperforms dacarbazine in a murine melanoma model.

Melanoma is a highly aggressive skin cancer. A paclitaxel formulation of solid lipid nanoparticles modified with Tyr-3-octreotide (PSM) is employed to treat melanoma that highly expresses somatostatin receptors (SSTRs). PSM exerts more apoptotic and anti-invasive effects in B16F10 mice melanoma cells as compared to dacarbazine (DTIC), an approved chemotherapeutic drug for treating aggressive melanoma. Besides, PSM induces one of the biomarkers of immunogenic cell death in vitro and in vivo as confirmed by calreticulin exposure on the B16F10 cell surface. We observed a significant number of CD8 positive T cells in the tumor bed of the PSM treated group. As a result, PSM effectively reduces tumor volume in vivo as compared to DTIC. PSM also induces a favorable systemic immune response as determined in the spleen and sera of the treated animals. Importantly, PSM can reduce the number of nodule formations in the experimental lung metastasis model. Our experimentations indicate that the metronomic PSM exhibits remarkable anti-melanoma activities without any observable toxicity. This immune modulation behavior of PSM can be exploited for the therapy of melanoma and probably for other malignancies.

A compact solvent extraction based 99Mo/99mTc generator for hospital radiopharmacy.

A compact and portable 99Mo-99 mTc generator based on solvent-extraction, mimic to the conventional 99Mo-99 mTc alumina column generator is much-needed commodity for use in hospital radiopharmacy setup. The present study includes the development of a portable, simple and low cost 99Mo/99 mTc-generator based on MEK solvent extraction technique to obtain a very high concentration of no-carrier added (nca) 99 mTc solution, where low specific activity 99Mo source is obtained through 98Mo(n, γ)99Mo reaction in a research reactor. The unit is intended for operation under the conditions of medical radiological laboratories. Technical trials showed that the mean time of preparation of sodium [99mTc] pertechnetate radiopharmaceutical did not exceed 15 min. The quality and yield of 99 mTc-pertechnetate is upto the mark for formulation of radiopharmaceuticals.

Radioactive ion beams of 111In using ECR plasma sputtering method.

Radioactive ion beams of 111In (indium-111, half-life 2.8 days) have been produced using the plasma sputtering method in an electron cyclotron resonance (ECR) ion source at the Variable Energy Cyclotron Centre RIB facility. Indium isotopes were first produced by bombarding a natural silver target with a 32 MeV, 40 µA alpha particle beam from the K-130 cyclotron. After radio-chemical separation, about 25 mCi In-chloride was deposited on an aluminum electrode and inserted in the plasma chamber of the ECR. Indium ions produced by ion induced sputtering in the plasma were extracted from the ion source, isotopically separated, and a pure 111In beam was measured at the focal plane of the separator. The measured 111In beam intensity was 2.67 × 105 particles/s for a beam energy of 5 keV.

A simple method for preparation of pure 68 Ga-acetate precursor for formulation of radiopharmaceuticals: Physicochemical characteristics of the 68 Ga eluate of the SnO2 based-68 Ge/68 Ga column generator.

Gallium-68 radioisotope is an excellent source in clinical positron emission tomography application due to its ease of availability from germanium-68 (68 Ge)/gallium-68 (68 Ga) generator having a shelf life of 1 year. In this paper, a modified method for purification of the primary eluate of 68 Ge-68 Ga generator by using a small cation exchange resin (Dowex-50) column has been described. The breakthrough of 68 Ge before and after purification of 68 Ga eluate was 0.014% and 0.00027%, respectively. The average recovery yield of 68 Ga after purification was 84% ± 8.6% (SD, n = 335). The results of the physiochemical studies confirmed that the 68 Ga-acetate obtained is suitable for labeling of radiopharmaceuticals.

Paclitaxel-loaded solid lipid nanoparticles modified with Tyr-3-octreotide for enhanced anti-angiogenic and anti-glioma therapy.

UNLABELLED: Somatostatin receptors (SSTRs) especially subtype 2 (SSTR2) are overexpressed in glioma. By taking advantage of the specific expression of SSTR2 on both glioma neovasculature endothelial cells and glioma cells, we constructed Tyr-3-octreotide (TOC)-modified solid lipid nanoparticles (SLN) loaded with paclitaxel (PTX) to enable tumor neovasculature and tumor cells dual-targeting chemotherapy. In this work, a TOC-polyethylene glycol-lipid (TOC-PEG-lipid) was successfully synthesized and used as a targeting molecule to enhance anticancer efficacy of PTX loaded sterically stabilized lipid nanoparticles. The prepared PTX-loaded SLN modified with TOC (PSM) was characterized by standard methods. In rat C6 glioma cells, PSM improved PTX induced apoptosis. Both tube formation assay and CD31 staining of treated orthotopic glioma tissues confirmed that PSM significantly improved the antiangiogenic ability of PTX in vitro and in vivo, respectively. Radiolabelled PSM achieved a much higher and specific accumulation within the glioma as suggested by the biodistribution and imaging studies. Furthermore, PSM exhibited improved anti-glioma efficacy over unmodified nanoparticles and Taxol in both subcutaneous and orthotopic tumor models. These findings collectively indicate that PSM holds great potential in improving the efficacy of anti-glioma therapy. STATEMENT OF SIGNIFICANCE: Somatostatin receptors (SSTRs) especially subtype 2 (SSTR2) are overexpressed in various mammalian cancer cells. Proliferating endothelial cells of neovasculature also express SSTR2. Tyr-3-octreotide (TOC) is a known ligand for SSTR2. We have successfully prepared paclitaxel-loaded solid lipid nanoparticles modified with TOC (PSM) having diameter less than 100nm. We found that PSM improved anti-cancer efficacy of paclitaxel in SSTR2 positive glioma of rats. This improved anti-glioma efficiency of PSM can be attributed to dual-targeting (i.e. tumor cell and neovasculature targeting) efficiency of PSM and promoted anti-cancer drug accumulation at tumor site due to TOC modification of solid lipid nanoparticles. This particular study aims at widening the scope of octreotide-derivative modified nanocarrier by exploring dual-targeting potential of PSM.

Synthesis and evaluation of technetium-99m-labeled bioreductive pharmacophores conjugated with amino acids and peptides for tumor imaging.

Development of molecular imaging agents to target tumor has become a major trend in nuclear medicine. With the aim to develop new potential 99mTc-radiopharmaceuticals for targeting tumor, we have synthesized 5-nitroimidazolyl amino acids and RGD-coupled 2-nitroimidazoles. Technetium-99m radiolabeling with high radiochemical purity (>90%) was achieved for all the compounds. The radiolabeled complexes exhibited substantial in vitro stability in saline, serum, and histidine solution (10(-2) m). Cell binding studies in EAC and B16F10 cell lines also revealed rapid and comparatively high cellular internalization. Among all the compounds studied, the binding of 99mTc(CO)3-5 to B16F10 cells was moderately inhibited by the competitive peptide c[RGDfV], suggesting specificity of the radioligand toward αvß3 receptor. However, no significant displacement of bound radioligand was observed when the binding of the 99mTc-labeled complexes to above cells was challenged with excess competitive peptide. Fluorescent microscopy study provided direct evidence of intracellular localization of 5(6)-carboxyfluorescein-labeled 2-nitroimidazolyl-RGD-peptide in αvß3-positive B16F10 mouse melanoma cell line. The ligands caused only 8-13% of hemolysis toward rat erythrocytes at concentrations as high as 100 µm. Imaging and biodistribution studies were performed in Swiss albino mice bearing induced tumor. 99mTc-1 and 99mTc(CO)3-5 demonstrated a very favorable in vivo profile. Selective uptake and retention in tumor with encouraging tumor/muscle and tumor/blood ratio and significant cellular uptake of fluorescence-labeled-2-nitroimidazolyl RGD indicate the great potentiality of the pharmacophore for further evaluation as potential molecular imaging agent in cancer diagnosis.

Formulation and evaluation of fixed-dose combination of bilayer gastroretentive matrix tablet containing atorvastatin as fast-release and atenolol as sustained-release.

The objective of the present study was to develop bilayer tablets of atorvastatin and atenolol that are characterized by initial fast-release of atorvastatin in the stomach and comply with the release requirements of sustained-release of atenolol. An amorphous, solvent evaporation inclusion complex of atorvastatin with ß -cyclodextrin, present in 1 : 3 (drug/cyclodextrin) molar ratio, was employed in the fast-release layer to enhance the dissolution of atorvastatin. Xanthan gum and guar gum were integrated in the sustained-release layer. Bilayer tablets composed of sustained-release layer (10% w/w of xanthan gum and guar gum) and fast-release layer [1 : 3 (drug/cyclodextrin)] showed the desired release profile. The atorvastatin contained in the fast-release layer showed an initial fast-release of more than 60% of its drug content within 2 h, followed by sustained release of the atenolol for a period of 12 h. The pharmacokinetic study illustrated that the fast absorption and increased oral bioavailability of atorvastatin as well as therapeutic concentration of atenolol in blood were made available through adoption of formulation strategy of bilayer tablets. It can be concluded that the bilayer tablets of atorvastatin and atenolol can be successfully employed for the treatment of hypertension and hypercholesterolemia together through oral administration of single tablet.

Polymers derived from Xanthomonas campesteris and Cyamopsis tetragonolobus used as retardant materials for the formulation of sustained release floating matrix tablet of atenolol.

The objective of the present study was to develop, optimize, in vitro, and in vivo evaluation of floating matrix tablet of atenolol using polymer blend derived from Xanthomonas campesteris and Cyamopsis tetragonolobus that are characterized by release requirements of sustained-release product and to improve the oral bioavailability of the drug. A 3(2) full factorial design was employed to optimize the tablets, where content of polymer blend (X1) and ratio of xanthan gum-to-guar gum (X2) were considered as independent variables. The effects of independent variables on dependent variables, i.e. floating time, diffusion exponent, and time to release 50% of atenolol were evaluated. The in vivo pharmacokinetic parameters of the optimized formulation were compared with the marketed sustained release formulation of atenolol (Aten(®)). The optimized formulation containing 20% (w/w) of polymer blend and 50:50 ratio of xanthan gum-to-guar gum was able to float more than 12h and showed the desired sustained drug release from the tablets. In vivo retention studies in rabbit stomach showed the gastric residence of tablet up to 6h. The in vivo study of optimized tablets illustrated significant improvement in the oral bioavailability of atenolol in rabbits. It can be concluded that floating matrix tablet of atenolol prepared by using xanthan gum and guar gum has potential for sustained release of the drug as well as improved oral bioavailability through enhanced gastric residence time of formulation in stomach.

Preparation and evaluation of SnO2-based 68Ge/68Ga generator made from 68Ge produced through (nat)Zn(α,xn) reaction.

(68)Ge was produced by (nat)Zn(α,xn)(68)Ge reaction and its production yield was 31.82 kBq/µAh (0.86 µCi/µAh) at the end of irradiation (EOI). A simple chromatographic method using a SnO2 column was employed to separate (68)Ge from the target material and the co-produced non-isotopic radioisotope impurities. (68)Ge retained in the column served as the (68)Ge/(68)Ga generator. Elution efficiency of the column was about 60%. First 2 ml of the eluate contained more than 95% of the elutable activity. Post-elution purification cum concentration was done with a small cation exchange resin column. The presence of the inactive tin ions in the (68)Ga eluate was determined by the ICP-OES technique and was found to be about 0.03 ppm. Radiochemical purity of the final (68)Ga preparation was more than 99.99% and it was found to be suitable for making complex with ethylenediamine-N,N,N',N'-tetrakis(methylene phosphonic acid) (EDTMP).

A computerized compact module for separation of (99m)Tc-radionuclide from molybdenum.

An automated closed cycle module for the separation and recovery of various isotopes, radioactive or non-radioactive, using solvent extraction and column chromatography techniques, and in particular, for separation and recovery of (99m)Tc from low-medium specific activity (99)Mo, is described. The module may also be applicable for separation of (99m)Tc produced in a cyclotron. The module is safe and reliable to avoid human interference and hazards posed by handling of radioactive and hazardous chemicals. The entire system of automation includes a user-friendly PC based graphical user interface (GUI) that actually supervises the process via an embedded system based electronic controller.

Preparation and evaluation of 99mTc-cefuroxime, a potential infection specific imaging agent: a reliable thin layer chromatographic system to delineate impurities from the 99mTc-antibiotic.

Technetium-99m labelled cefuroxime, a second-generation cephalosporin antibiotic and potential bacteria specific infection imaging agent was evaluated. A good radiochemical purity (95%) of the labelled product was obtained after filtering the reaction mixture through a 0.22 µm filter. Scintigraphy study of the purified product showed uptake in infectious lesions 45 min after injection and abscess-to-muscle ratios were found to be 1.80, 1.85 and 1.88 at 45 min, 1.5 hr and 3 hr, respectively. A versatile and reliable chromatographic technique to assess the radiochemical purity of (99m)Tc-cefuroxime has also been described.

Production of 61Cu using natural cobalt target and its separation using ascorbic acid and common anion exchange resin.

(61)Cu was produced by (nat)Co(α, xn)(61)Cu reaction. (61)Cu production yield was 89.5 MBq/µAh (2.42 mCi/µAh) at the end of irradiation (EOI). A simple radiochemical separation method using anion exchange resin and ascorbic acid has been employed to separate the product radionuclide from inactive target material and co-produced non-isotopic impurities. The radiochemical separation yield was about 90%. Radiochemical purity of (61)Cu was >99% 1 h after EOI. Final product was suitable for making complex with N(2)S(2) type of ligands.

Recovery of 131I from alkaline solution of n-irradiated tellurium target using a tiny Dowex-1 column.

A simple and inexpensive ion-exchange chromatography method for the separation of medically useful no-carrier-added (nca) iodine radionuclides from bulk amounts of irradiated tellurium dioxide (TeO(2)) target was developed and tested using (131)I. The radiochemical separation was performed using a very small Dowex-1x8 ion-exchange column. The overall radiochemical yield for the complete separation of (131)I was 92+/-1.8 (standard deviation) % (n=8). The separated nca (131)I was of high, approximately 99%, radionuclidic and radiochemical purity and did not contain detectable amounts of the target material. This method may be adopted for the radiochemical separation of other different iodine radionuclides produced from tellurium matrices through cyclotron as well as reactor irradiation.

A simple and rapid technique for recovery of 99mTc from low specific activity (n,gamma)99Mo based on solid-liquid extraction and column chromatography methodologies.

A simple and inexpensive method has been developed for the separation of (99m)Tc from (99)Mo produced from the neutron activation of (98)Mo by (98)Mo(n,gamma)(99)Mo nuclear reaction. The recovery of (99m)Tc was performed by solid-liquid extraction based on alumina column chromatography. The overall radiochemical yield for the complete separation of (99m)Tc was 85-97% (n=5). The separated Na[(99m)Tc]TcO(4) was of high radionuclidic, radiochemical and chemical purities. The method can be adopted for routine processing and use of (99m)Tc in radiopharmacy operations.

A simple and rapid technique for recovery of (99m)Tc from low specific activity (n,gamma)(99)Mo based on solvent extraction and column chromatography.

A simple and inexpensive method of separation of (99m)Tc from (99)Mo produced by neutron activation of (98)Mo via the (98)Mo(n,gamma)(99)Mo nuclear reaction is described. The recovery of (99m)Tc was performed by solvent extraction technique followed by column (active alumina) chromatography. The overall radiochemical yield for the complete separation of (99m)Tc was 85-95% (n=10). The separated Na[(99m)Tc]TcO(4) was of high radionuclidic, radiochemical, and chemical purities. The method can be adopted for routine use of (99m)Tc in hospital radio-pharmacies utilizing low-medium specific activity (n,gamma)(99)Mo produced in a research reactor.

Synthesis and evaluation of (99m)Tc-moxifloxacin, a potential infection specific imaging agent.

To synthesize and evaluate a (99m)Tc labeled fluroquinolone, moxifloxacin as a potential bacteria specific infection imaging agent. A radiolabeling formulation including moxifloxacin, [Moxicip(TM) injection, Cipla] (4mg), sodium pertechnetate and stannous chloride (5microg) gave the best radiolabeling efficiency and moderately stable labeled (99m)Tc moxifloxacin. Quality control analysis was performed by ITLC. Rats and rabbit with infectious intramuscular lesions induced in either thigh with E. Colli were used for studying biodistribution and scintigraphic imaging of the labeled product. Imaging of an infected thigh of a rabbit was performed with a gamma-camera at various intervals. A good radiolabeling efficiency (90-95%) was obtained within 5min. No purification of the labeled product was done. Labeled product retained its radiochemical purity upto 85% even at 3h. Scintigraphy showed uptake in infectious lesions at 30min after injection, which remains constant upto 3h study. Abscess-to-muscle ratios were 1.60, 1.62, 1.74 and 1.75 at 30min, 1, 2 and 3h, respectively. Thus, (99m)Tc moxifloxacin, a new potential radiopharmaceutical has been developed for infection imaging agent.