Vial Kit Research Articles

Formulation of patient dose of [177Lu]Lu-Trastuzumab using in-house developed freeze-dried kit: A path forward for clinical translation.

Trastuzumab is a US-FDA-approved humanized monoclonal antibody used for the treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. The aim of the present work is to optimize a freeze-dried formulation of DOTA-Trastuzumab conjugate for the preparation of patient doses of [177Lu]Lu-Trastuzumab for radioimmunotherapy of breast cancer. The formulation of [177Lu]Lu-Trastuzumab usually takes a long time, and thus, such a process is not suitable for the routine preparation of this agent in hospital radiopharmacies. To circumvent this, a pre-synthesized DOTA-Trastuzumab conjugate as a freeze-dried formulation is proposed. In the present work, DOTA-Trastuzumab conjugate was subjected to a freeze-drying process after the addition of optimized amounts of radioprotectant and cryoprotectant. [177Lu]Lu-DOTA-Trastuzumab was prepared by incubating the lyophilized powder of the kit vial with medium-specific activity 177LuCl3. The final radiochemical purity of [177Lu]Lu-DOTA-Trastuzumab, prepared using freeze-dried kit, was determined to be >95%. To ascertain the reproducibility of the procedure, six consecutive batches of the freeze-dried formulation were prepared, radiolabeled, and evaluated by carrying out both in vitro and ex vivo studies. The consistency of the results of all the six consecutive batches confirmed the robustness and utility of the in-house optimized freeze-dried formulation for the preparation of patient doses of [177Lu]Lu-Trastuzumab at hospital radiopharmacies.

The GRPR Antagonist [99mTc]Tc-maSSS-PEG2-RM26 towards Phase I Clinical Trial: Kit Preparation, Characterization and Toxicity.

Gastrin-releasing peptide receptors (GRPRs) are overexpressed in the majority of primary prostate tumors and in prostatic lymph node and bone metastases. Several GRPR antagonists were developed for SPECT and PET imaging of prostate cancer. We previously reported a preclinical evaluation of the GRPR antagonist [99mTc]Tc-maSSS-PEG2-RM26 (based on [D-Phe6, Sta13, Leu14-NH2]BBN(6-14)) which bound to GRPR with high affinity and had a favorable biodistribution profile in tumor-bearing animal models. In this study, we aimed to prepare and test kits for prospective use in an early-phase clinical study. The kits were prepared to allow for a one-pot single-step radiolabeling with technetium-99m pertechnetate. The kit vials were tested for sterility and labeling efficacy. The radiolabeled by using the kit GRPR antagonist was evaluated in vitro for binding specificity to GRPR on PC-3 cells (GRPR-positive). In vivo, the toxicity of the kit constituents was evaluated in rats. The labeling efficacy of the kits stored at 4 °C was monitored for 18 months. The biological properties of [99mTc]Tc-maSSS-PEG2-RM26, which were obtained after this period, were examined both in vitro and in vivo. The one-pot (gluconic acid, ethylenediaminetetraacetic acid, stannous chloride, and maSSS-PEG2-RM26) single-step radiolabeling with technetium-99m was successful with high radiochemical yields (>97%) and high molar activities (16-24 MBq/nmol). The radiolabeled peptide maintained its binding properties to GRPR. The kit constituents were sterile and non-toxic when tested in living subjects. In conclusion, the prepared kit is considered safe in animal models and can be further evaluated for use in clinics.

Evaluation of Tetrofosmin Cold Kit Fractionation Using Alternative New Method of Quality Control for Testing Radiochemical Purity

Objective The aim of this study is to establish a method for the fractionation of tetrofosmin cold kit under different storage conditions and to optimize an alternate chromatography method from the reference method to test radiochemical purity (RCP). Materials and Methods Tetrofosmin cold kit vial was fractionated aseptically in six equal fractions and stored in vials and syringes. To test the stability of the reconstituted solution for a longer duration, the mother vials and syringes were stored at two different temperatures, that is, at 4°C and at -20°C till further used. Radiolabeling of fractionated tetrofosmin was performed as per the standard labeling protocol. Radionuclide purity, radioassay, and pH were tested. Radiolabeling efficiency and RCP were determined by paper chromatography. Results Radionuclide purity of eluate was greater than 99.9%. The pH of technetium-99m (Tc-99m) eluate and Tc-99m tetrofosmin was between 4.5-7.5 and 7.5-9.5, respectively. The deviation in the radioactivity during all measurements was less than 1%. The kits fractioned in glass vials resulted in higher radiolabeling yield and RCP as compared with kits fractionated in syringes. The RCP of glass vial versus syringe was observed to be greater than 95 versus 90% and 95 versus 80% at -20°C and 4°C, respectively. Conclusion Tetrofosmin kit can be used in a cost-effective manner by fractionation. One tetrofosmin vial can be used in six fractions for up to 15 days when stored at -20°C and 4°C freezer temperature. The alternative method to check the RCP of Tc-99m tetrofosmin is safer and less time consuming as compared with the reference method.

Preparation of Rhenium-188-Lipiodol Using Freeze-Dried Kits for Transarterial Radioembolization: An Overview and Experience in a Hospital Radiopharmacy.

Background: Rhenium-188(188Re)-lipiodol is a clinically effective, economically viable radiopharmaceutical for Selective Internal Radiation Therapy of liver cancer. Present study evaluates the performance of three freeze-dried kits with respect to the radiochemistry, quality control, and overall "ease of preparation" aspects in a hospital radiopharmacy. Materials and Methods: Freeze-dried kits of acetylated 4-hexadecyl-4,7-diaza-1,10-decanedithiol (AHDD), super six sulfur (SSS), and diethyl dithiocarbamate (DEDC), obtained commercially or received as gift, were used for the preparation of 188Re-lipiodol using freshly eluted 188Re-sodium perrhenate from commercial Tungsten-188/188Re generator following recommended procedures. Results: The overall yield of 188Re-lipiodol prepared using AHDD Kit, SSS Kit, and DEDC Kit was 74.82% ± 3.3%, 87.55% ± 4.8%, and 76.38% ± 4.6%, respectively. Observed radiochemical purity (RCP) of 188Re-lipiodol prepared using these kits was 88.65% ± 2.8%, 92.92% ± 3.0%, and 91.38% ± 3.0%, respectively. Using a modified version of the DEDC Kits, overall yield of 87.17% ± 2.7% and RCP of 95.43% ± 2.3% could be achieved. Conclusions: While all three freeze-dried kits can be used for the preparation of 188Re-lipiodol in >70% overall yield, the modified version of DEDC Kits has some advantages in terms of preparation time and volume of Rhenium-188 activity that can be added to the kit vial. The latter feature of the DEDC Kit is particularly useful for patient dose preparation with 188Re activity of low radioactive concentration.

Feasibility of a Scale-down Production of [68Ga]Ga-NODAGA-Exendin-4 in a Hospital Based Radiopharmacy.

Glucagon-like peptide 1 receptor (GLP-1R) is preferentially expressed in β-cells, but it is highly expressed in human insulinomas and gastrinomas. Several GLP-1 receptor- avid radioligands have been developed to image insulin-secreting tumors or to provide a quantitative in vivo biomarker of pancreatic β-cell mass. Exendin-4 is a high affinity ligand of the GLP1- R, which is a candidate for being labeled with a PET isotope and used for imaging purposes. Here, we report the development and validation results of a semi-manual procedure to label [Lys40,Nle14(Ahx-NODAGA)NH2]exendin-4, with Ga-68. A68Ge/68Ga Generator (GalliaPharma®, Eckert and Ziegler) was eluted with 0.1M HCl on an automated synthesis module (Scintomics GRP®). The peptide contained in the kit vial (Radioisotope Center POLATOM) in different amounts (10-20-30 μg) was reconstituted with 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethansulfonic acid (HEPES) solution and 68GaCl3 (400-900 MBq), followed by 10 min incubation at 95°C. The reaction solution was then purified through an Oasis HLB column. The radiopharmaceutical product was tested for quality controls (CQs) in accordance with the European Pharmacopoeia standards. The synthesis of [68Ga]Ga-NODAGA-Exendin-4 provided optimal results with 10 μg of peptide, getting the best radiochemical yield (23.53 ± 2.4%), molar activity (100 GBq/μmol) and radiochemical purity (91.69%). The study developed an imaging tool [68Ga]Ga-NODAGA-Exendin-4, avoiding pharmacological effects of exendin-4, for the clinical community.

Rhenium-188 Hydroxyethane 1,1-Diphosphonic Acid (HEDP) for Bone Pain Palliation Using BARC-HEDP Kits versus Pars-HEDP Kits: A Comparison on Preparation and Performance Aspects at Hospital Radiopharmacy.

Purpose of the Study:Rhenium-188 hydroxyethane 1,1-diphosphonic acid (HEDP) is a clinically established radiopharmaceutical for palliation of bone pain due to osseous metastases. Recently, the Bhabha Atomic Research Centre (BARC) had developed a freeze-dried kit for the preparation of rhenium-188 HEDP. The present study compares the radiochemistry aspects of indigenous BARC-HEDP kits with commercially available HEDP kits from Pars Isotope Company, Iran.Materials and Methods:Freeze-dried HEDP kits were obtained from Radiopharmaceuticals Division, BARC, and Pars Isotope Company, Iran. Following recommended procedures, rhenium-188 HEDP was prepared using freeze-dried kits from both sources using freshly eluted rhenium-188 sodium perrhenate obtained from a commercial tungsten-188/rhenium-188 generator.Results:Both kits could be used for the preparation of rhenium-188 HEDP in >95% radiochemical purity (RCP). Rhenium-188 HEDP prepared from both kits showed comparable in vitro stability as well as pharmacokinetic properties. The normal bone-to-soft tissue ratio observed for rhenium-188 HEDP prepared using BARC-HEDP kit and Pars-HEDP kit was 1.993 and 1.416, respectively.Conclusions:Both HEDP kits provided a user-friendly solution for the preparation of rhenium-188 HEDP. While Pars-HEDP-kit permits the addition of only 2 mL of rhenium-188 perrhenate solution per kit vial, BARC-HEDP-kit allows up to 5 mL. This feature permits the preparation of patient dose of rhenium-188 HEDP even with older generators providing rhenium-188 perrhenate having a low radioactive concentration (activity/mL). In addition, availability of an indigenous product is always preferable over imported options.

The Application of Enzymological Techniques for Determination of the Inhibitor Activity of Bio Enzym Extracted from Seawater Bacteria Pseudomonas aerogenosa to Fight Biocorrosion of Carbon Steel

The paper presents a studies for the development of new corrosion inhibitors by biotechnological way applicable to many areas of petroleum industry including, characterization of protective films on carbon steel and biocorrosion inhibition. Our research is oriented towards the isolation of new strains of bacteria from the sea waters of the Mediterranean region that have power (inhibitory and/or bactericidal that blocks the growth of sulfate-reducing bacteria responsible for microbiologically influenced by production of Pyocyanin (1 hydroxyphenazin) or 5-methylphenazin-1-one. Our first objective was to isolate the population of Pseudomonas Aerugenosa on a specific medium, characterization gram, then fermentation in a nutrient broth. The second objective of this study is evaluation of corrosion rate by weight loss method with injecting different dose of the crude enzyme extract CEE containing the methylphenazine (Pyocyanin). An efficacy test was performed on test kit vials containing the specific culture medium with the SRB contaminated with industrial injection water from SONAHESS region. The total disappearance of the SRB is 40% of CEE by blocking their metabolism in the growth phase confirms the efficiency of treatment.

Evaluation of a Flexible NOTA-RGD Kit Solution Using Gallium-68 from Different 68Ge/68Ga-Generators: Pharmacokinetics and Biodistribution in Nonhuman Primates and Demonstration of Solitary Pulmonary Nodule Imaging in Humans.

Radiopharmaceuticals containing the motive tripeptide arginyl-glycyl-asparatic acid (RGD) are known to target ανβ3 integrins during tumor angiogenesis. A more generic kit radiolabeling procedure accommodating Ga-68 from different generators was developed for NOTA-RGD and evaluated for its versatile use and safety in subsequent in vivo applications. The [68Ga]NOTA-RGD kit was further verified for its expected biodistribution and pharmacokinetics in nonhuman primates and its clinical sensitivity to detect solitary pulmonary nodules (SPN) in cancer patients. Single vial kits containing 28-56nmol of NOTA-cyclo-Arg-Gly-Asp-d-Tyr-Lys (NOTA-RGD) and sodium acetate trihydrate buffer were formulated. Versatility of the NOTA-RGD radiolabeling performance and adaption to a TiO2- and a SnO2-based generator type, characterization and long-term storage stability of the kits were carried out. The blood clearance and urine recovery kinetics as well as the image-guided biodistribution of [68Ga]NOTA-RGD was studied in a vervet monkey model. [68Ga]NOTA-RGD kits were further tested clinically to target solitary pulmonary nodules. The kits could be successfully formulated warranting integrity over 3-4months with a good [68Ga]NOTA-RGD radiolabeling performance (radiochemical purity >95%, decay corrected yield 76-94%, specific activity of 8.8-37.9GBq/μmol) The kits met all quality requirements to be further tested in vivo. [68Ga]NOTA-RGD cleared rapidly from blood and was majorly excreted via the renal route. The liver, spleen, heart and intestines showed initial uptake with steadily declining tissue activity concentration over time. In addition, the [68Ga]NOTA-RGD kit allowed for delineation of SPN from non-malignant lung tissue in humans. A more versatile radiolabeling procedure using kit-formulated NOTA-RGD and different generator types was achieved. The uncompromised in vivo behavior and efficient targeting of SPN warrants further investigations on the clinical relevance of [68Ga]NOTA-RGD derivatives to implement initial guidelines and management of patients, with regard to integrin targeted imaging.

A tri-modal molecular imaging agent for sentinel lymph node mapping

IntroductionWe report an “instant kit” method to radiolabel fluorescent-tilmanocept with 68Ga and 99mTc for tri-modal molecular imaging of sentinel lymph nodes (SLNs). MethodsSolutions of sodium acetate, 68GaCl3 and Na99mTcO4 were added successively to a “kit vial” containing lyophilized 800CW-tilmanocept, SnCl2, trehalose and ascorbic acid. After a 30-min incubation, the pH was neutralized with PBS. No purification was required. Radiochemical and fluorescence purity was measured by HPLC and ITLC techniques. In vitro stability was measured by standing gel chromatography (SGC) and ITLC by a 100-fold dilution 0.25h after radiolabeling. In vivo stability was measured by SGC and ITLC after an 11h incubation in human plasma. A dose (0.1nmol, ~1MBq 68Ga, ~25MBq 99mTc) was injected to the footpad of 4 mice. Popliteal SLNs were imaged by PET and fluorescence imaging systems at 0.5, 24, 48, 72h, then excised and assayed for 99mTc. ResultsRadiochemical and fluorescent purity exceeded 98%. The in vitro stability assay demonstrated high irreversibility of both radiolabels and the fluorescent label, and in vivo stability assay demonstrated high stability of the technetium and fluorescent labels to plasma metabolism. Popliteal SLNs were identified by PET and fluorescence imaging within 0.5h of injection. SLN fluorescence intensity remained constant for 72h, when ~1% of the injected dose resided in the SLN. ConclusionsFluorescent-labeled tilmanocept can be radiolabeled with 68Ga and 99mTc by the sequential addition of each generator eluate to a lyophilized kit. The resulting tri-modal agent provides: PET images for pre-operative SLN mapping, fluorescence imaging up to 72hours after injection, and quantitative radiometric measurement of SLN accumulation after excision.

Studies on the Labeling of Ethylenediaminetetramethylene Phosphonic Acid, Methylene Diphosphonate, Sodium Pyrophosphate and Hydroxyapatite with Lutetium-177 for use in Nuclear Medicine.

For the treatment of skeletal metastasis, a therapeutic radionuclide tagged with a bone seeking ligand is required, while for radiation synovectomy (RS), a therapeutic radionuclide irreversibly attached to pre-formed particles of appropriate size is required. Radio lanthanides are mostly therapeutic, and ligands containing phosphate groups are predominantly bone seekers. Exploiting these facts, number of new therapeutic radiopharmaceuticals could be developed. Labeling of four phosphate containing materials was pursued in the present study. It was hypothesized that various 177Lu-labeled bone-seeking complexes such as 177Lu-ethylenediaminetetramethylene phosphonic acid (EDTMP), 177Lu-methylene diphosphonate (MDP) and 177Lu-pyrophosphate (PYP) could be developed as agents for palliative radiotherapy of bone pain due to skeletal metastases, and 177Lu-Hydroxyapatite (HA) could be developed as an agent for radiosynovectomy of small joints. Lyophilized kit vials of EDTMP, MDP and sodium pyrophosphate (Na-PYP) were formulated. HA particles were synthesized locally and purity was checked by high-performance liquid chromatography (HPLC). 177Lu was labeled with EDTMP, MDP, PYP, and HA and the behavior of all was studied by radio-thin layer chromatography (TLC) radio-HPLC and radio-electrophoresis. Radio-TLC confirmed the labeling. HPLC analysis too verified the labeling. Radio-electrophoresis results depicted peaks for 177Lu-MDP, 177Lu-EDTMP and 177Lu-PYP at 3.37 ± 0.06 cm, 5.53 ± 0.15 cm and 7.03 ± 0.06 cm respectively confirming negative charge on each specie as all migrated toward positive anode. All 3 methods verified the labeling. The study demonstrated that EDTMP, MDP and PYP form stable complexes with 177Lu in injectable solution form. HA particulates could too be labeled with 177Lu with high radiochemical yields (>98%) in suspension form. Former three could be utilized as bone-pain palliation agents for the treatment of bone metastases, and the later could be applied for the treatment of Rheumatoid arthritis of small joints. The study has also indicated the possibility of developing other numerous radiolanthanide analogs with the potentials of possible use in radiation therapy.

Formulation, preclinical evaluation, and preliminary clinical investigation of an in-house freeze-dried EDTMP kit suitable for the preparation of 177Lu-EDTMP.

The objective of the present work was to develop a freeze-dried ethylenediaminetetramethylene phosphonic acid (EDTMP) kit, suitable for the convenient and single-step preparation of (177)Lu-EDTMP, which is currently being evaluated as a promising radiopharmaceutical for providing palliative care to patients suffering from skeletal metastases and to assess the potential of the agent in human patients. Lyophilized EDTMP kits having identical composition with Quadramet(®) were prepared using EDTMP, NaOH, and anhydrous CaCO3. The (177)Lu-EDTMP patient dose was prepared by incubating the kit materials dissolved in 1 mL of water for injection and (177)LuCl3, produced in-house, at room temperature for 15 minutes. Pharmacokinetic behavior of the agent was studied by carrying out biodistribution and scintigraphic imaging studies in normal Wistar rats. Clinical studies were performed by administering the preparation in patients suffering from disseminated skeletal metastases. Five batches of freeze-dried EDTMP kits with 50 kit vials in each batch were prepared. Each kit vial comprised a lyophilized mixture of 35 mg EDTMP, 14.1 mg NaOH, and 5.8 mg of CaCO3. The (177)Lu-EDTMP complex was prepared with excellent radiochemical purity (>99%) and high stability (>98% until 9 days postpreparation) using these kits. Radiochemical studies showed that this kit could be used within a pH range of 6-9 and with (177)Lu having specific activity as low as 925 GBq · g(-1) (25 Ci · g(-1)) for the preparation of up to 3.7 GBq (100 mCi) of (177)Lu-EDTMP. Biodistribution studies in animals revealed selective accumulation of the agent in skeleton (∼ 60% of the injected activity) with major renal clearance. Preliminary clinical studies in 10 patients exhibited selective accumulation of the radiotracer in skeletal lesions and provided significant pain relief thereby improving the quality of life of the patients. Freeze-dried EDTMP kits, suitable for the preparation of patient doses of (177)Lu-EDTMP, have been developed and used in preliminary studies for treating the cancer patients with disseminated skeletal metastases. The kit may also find use for the preparation of other potential bone pain palliation agents, such as (153)Sm-EDTMP.

Improved kit formulation for preparation of (99m)Tc-HYNIC-TOC: results of preliminary clinical evaluation in imaging patients with neuroendocrine tumors.

(99m)Tc-HYNIC-TOC is a cost-effective and logistically viable agent for scintigraphy of neuroendocrine tumors overexpressing somatostatin receptors as compared with [(111)In-DTPA-D-Phe(1)] Octreotide (Octreoscan(®)). Several studies have been reported, wherein the efficacy of this agent is demonstrated. In the present article, the authors report the preparation of a single-vial HYNIC-TOC kit suitable for the preparation of 4-5 patient doses (15 mCi/patient) of (99m)Tc-HYNIC-TOC. The kits were tested for sterility and bacterial endotoxins to assure safety of the product. A significant modification in this kit is the inclusion of buffer in the kit itself, unlike in commercially available kits where the buffer solution has to be added during preparation. (99m)Tc-HYNIC-TOC was prepared by adding 20-80 mCi (740-2960 MBq) of freshly eluted Na(99m)TcO4 in 1-3 mL of sterile saline directly into the kit vial and heating the vial in a water bath at 100°C for 20 minutes. The labeling yield and radiochemical purity of (99m)Tc-HYNIC-TOC, prepared using the lyophilized cold kit, were consistently >90%. The kits were evaluated over a period of 9 months and found to be stable when stored at -20°C. Limited clinical studies performed with the (99m)Tc-HYNIC-TOC, formulated using the kit, showed adequate sensitivity and specificity for the detection of gasteroenteropancreatic neuroendocrine tumors.

Synthesis ofS-thiomethyl MAG3, radiolabelling with technetium-99m and biological evaluation

Protection of the thiolate function of the mercaptoacetyltriglycine (MAG3) by S-thiomethyl group allows automatic deprotection of the protecting group during technetium-99m radiolabelling by transchelation using stannous chloride dihydrate as reductant. Protection of the thiolate group with S-thiomethyl increases the stability of the ligand, desired complex of high radiochemical purity could be prepared under relatively mild labelling condition (at room temperature) omitting the aeration step. The complex prepared from the S-thiomethyl protected MAG3 ligand were chromatographically (HPLC) and biologically compared with the corresponding complex prepared from the S-benzoylated MAG3 precursor. This result suggests that technetium-99m complex of MAG3 could be prepared from S-thiomethylated MAG3 precursor in comparatively higher purity under relatively milder labelling condition and this method of radiolabelling could be used for the development of less cumbrous single vial MAG3 kit. Copyright © 2012 John Wiley & Sons, Ltd.

A kit to prepare 111In-DTPA-trastuzumab (Herceptin) Fab fragments injection under GMP conditions for imaging or radioimmunoguided surgery of HER2-positive breast cancer

The human epidermal growth factor receptor-2 (HER2) gene is amplified in 25% of invasive breast cancers, and receptor overexpression has been noted in up to 60% of early stages of the disease [ductal carcinoma in situ (DCIS)]. Preclinical studies have revealed high tumor/blood ratios (>27:1) for (111)In-labeled Fab fragments of the HER2 monoclonal antibody, trastuzumab (Herceptin) ((111)In-DTPA-trastuzumab Fab) at 72 h pi in athymic mice bearing subcutaneous human breast cancer xenografts. Our aim in this study was to formulate a kit for preparation of (111)In-DTPA-trastuzumab Fab injection under good manufacturing practice (GMP) conditions suitable for human administration in a Phase I clinical trial of imaging and radioimmunoguided surgery (RIGS) of HER2-positive breast cancer. Fab fragments were produced by digestion of trastuzumab IgG (Herceptin) with immobilized papain for 20 h at 37°C. Fab fragments were purified by ultrafiltration, then reacted with a 10-fold molar excess of diethylenetriaminepentaacetic acid (DTPA) dianhydride. DTPA-Fab fragments were purified, then sterilized by filtration into unit dose glass vials (kits). Kits were tested against specifications for volume (0.9-1.1 ml), protein concentration (0.45-0.55 mg/ml), pH (5.5-6.5), DTPA substitution (0.5-4.0 mol DTPA/mol Fab), appearance (clear, colorless and particle free), labeling efficiency (≥ 85%), and sterility and apyrogenicity (USP XXXII). Immunoreactivity of (111)In-DTPA-trastuzumab Fab towards HER2 was measured by saturation radioligand binding assays using SKBR-3 human breast cancer cells (specifications: K(a) = 0.6-9.6 × 10(7) L/mol; B(max) = 0.6-10.4 × 10(6) sites/cell). (111)In-DTPA-trastuzumab Fab injection was prepared by adding 80-100 MBq of (111)InCl(3) to a single kit vial and incubating for 30 min at room temperature. (111)In-DTPA-trastuzumab Fab was assayed for the amount of radioactivity and tested for pH, radiochemical purity (RCP), appearance and sterility. Pure and homogeneous Fab fragments were produced. Eleven lots of kits met established quality specifications. The labeling efficiency with (111)In was 90.6 ± 2.2%. (111)In-DTPA-trastuzumab Fab bound specifically to HER2 on SKBR-3 cells (K(a) = 4.8 ± 2.5 × 10(7) L/mol and B(max) = 1.6 ± 0.8 × 10(6) sites/cell). Thirteen lots of (111)In-DTPA-trastuzumab injection met all established specifications. Kits were stable for 90 days and (111)In-DTPA-trastuzumab Fab injection was stable for 24 h stored at 4 °C. A kit was formulated under GMP conditions for the preparation of (111)In-DTPA-trastuzumab Fab injection suitable for human administration. The kits were approved by Health Canada.

A pharmacokinetic comparison of the Marqibo 3 and 5 vial injection kits in metatastic melanoma patients

8575 Background: In nonclinical and clinical studies, liposomal encapsulation of vincristine sulfate (VCR) increased the circulation time and accumulation of VCR at the tumor site, and thus improved antitumor efficacy in comparison to VCR. Marqibo (vincristine sulfate liposomes injection) may be administered safely at doses exceeding that typically employed by VCR, with a manageable pattern of clinical toxicities consistent with VCR. Methods: We conducted a phase I, single-center, open-label, randomized, 2-arm crossover study designed to compare the pharmacokinetics (PK) of Marqibo utilizing the 3- and 5-vial kits administered 2 mg/m2 IV infusion once every 2 weeks in histologically confirmed, surgically nonresectable Stage III or IV metastatic cutaneous, mucosal, or choroidal melanoma patients. Patients randomized to receive the 3-vial kit at Cycle 1 were crossed over to receive the 5-vial kit at Cycle 2 or vice versa. The 3-vial kit was used for all patients at all cycles from Cycle 3 to end of treatment. Antitumor activity was assessed by CT scan every 4 cycles. Blood samples for PK analysis was collected at pretreatment, during infusion, end of infusion, and at various time points within 96 hours post end of infusion at Cycles 1 and 2. Total VCR concentration and released vincristine concentration was measured using HPLC-MS/MS method. Results: Fifteen patients were enrolled and treated; 11 were evaluable for the PK analysis. Median number of cycles received was 4 (1- 24). Objective response was observed in 13% (1 CR, 1 PR) or stable disease (20%, 3 SD) as their best response. The 90% CI (0.83–1.12) on the ratio of the means of the AUC0-inf of the 3- and 5-vial kits was within the interval of 0.80–1.25 confirming the bioequivalence of the two kits. Seventy-three percent discontinued treatment due to disease progression and 13% discontinued due to adverse events. Adverse events included hypoesthesia or paresthesia, constipation, numbness, weakness, fatigue, nausea, vomiting. Conclusions: Single agent Marqibo demonstrated moderate activity in advanced Stage IV melanoma patients and was generally well tolerated with similar adverse event profile to VCR. The 3- and 5-vial kits produced similar bioequivalent PK profiles. No significant financial relationships to disclose.

The effect on radiochemical purity of modifications to the method of preparation and dilution of 99mTc-sestamibi

99mTc-sestamibi is a useful radiopharmaceutical for myocardial perfusion imaging, parathyroid imaging and breast tumour imaging. However, the preparation is time consuming and the limit of 3 ml on the volume of liquid that can be added to the Cardiolite kit vial means that it is often difficult to draw up small doses for patient studies. To modify the method of preparation of 99mTc-sestamibi in order to reduce the preparation time and to give a preparation which is more convenient for withdrawing patient doses. A modified kit was prepared by reconstituting a Cardiolite kit vial with 3 ml Sodium Chloride Injection (0.9%) BP, sub-dividing it into two separate nitrogen-filled vials before adding sodium pertechnetate and boiling for radiolabelling. 99mTc-sestamibi was also prepared according to the manufacturer's recommended method and diluted with sodium chloride injection after preparation. Radiochemical purity was assessed by thin-layer chromatography and high-performance liquid chromatography. 99mTc-sestamibi prepared according to the manufacturer's recommended method had high radiochemical purity (96.9%+/-1.1%) and retained >90% radiochemical purity over 8 h following dilution. However, 99mTc-sestamibi prepared by the modified method gave variable and inconsistent results. The modified method of preparation was not robust enough to give reproducibly high radiochemical purity. However, dilution of 99mTc-sestamibi prepared according to the manufacturer's recommended method was satisfactory. This study highlights problems with the analysis of 99mTc-sestamibi and the limitations of modifying the method of preparation.

Preparation of 99mTc-ethylene dicysteine (99mTc-EC) by transchelation using 99mTc-glucoheptonate (99mTc-GHA) and its evaluation for renal function studies.

The complexation of ethylene dicysteine (EC) with 99mTc needs to be carried out at pH 12 to achieve a high radiochemical yield. However, the preparation of the kit at high pH poses difficulties and requires very stringent preparation conditions, as stannous tin, one of the main ingredients in the kit, is unstable at high pH. Hence, an alternative method, involving the transchelation preparation of 99mTc-EC using 99mTc-glucoheptonate (99mTc-GHA) prepared at pH 6.5, was attempted, prompted by the reported success of the preparation of 99mTc-sestamibi (99mTc-MIBI) by this method. The preparation of 99mTc-EC by this method first involved the formation of 99mTc-GHA by the addition of sodium pertechnetate-99mTc to the Sn-GHA kit vial at pH 6.5. 99mTc-EC was formed by the addition of reconstituted EC solution at pH approximately 12 to the preformed 99mTc-GHA. The reaction was allowed to proceed both at room temperature and on a boiling water bath. The pH of the final product was adjusted to pH approximately 7 with 0.5 M phosphate buffer at pH 4-5, without affecting the quality of the product. The urinary excretion of 99mTc-EC prepared by transchelation, tested in mice, was similar to that of directly prepared 99mTc-EC, indicating that the final product prepared by the two methods was the same. The clinical evaluation of the product formulated by the new procedure showed satisfactory findings, comparable with the reports in the literature.

Technetium-99m-tetrofosmin: retention of nitrogen atmosphere in kit vial as a cause of poor quality material.

Technetium-99m (99Tc(m))-tetrofosmin was prepared using four different reconstitution methods. The radiochemical purity (RCP) of these products was assessed 8 h later using thin layer chromatography (TLC). Material produced using the original method supplied by the manufacturer and using an newer method, which involves the use of a vent needle and the addition of air, had acceptable RCP (mean +/- SD 94.2 +/- 1.1% and 94.7 +/- 1.7%, respectively) and similar chromatograms. In addition, both products showed good clinical efficacy and exhibited normal biodistribution behaviour. Preparing 99Tc(m)-tetrofosmin using the two other methods, one using a high radioactive concentration and the other maintaining the nitrogen content of the kit vial, gave rise to chromatograms with reduced RCP (63.5 +/- 10.9% and 61.9 +/- 7.6%, respectively) and greater levels of impurities. Although neither of these last two preparations was used clinically, we suggest that reports of poor quality images may be the result of administration of materials similar to these. Results for the high radioactive concentration method were as expected and are consistent with the restrictions imposed by the manufacturer. However, results using the last method are surprising and would suggest that the production of good quality 99Tc(m)-tetrofosmin is dependent on the quantity of nitrogen in the kit vial. We believe that the amount of nitrogen removed from the kit vial during the process of reconstitution is critical. If too much nitrogen is present this will result in poor quality material. In practice it is conceivable that there could be occasions when insufficient nitrogen is removed when following the manufacturer's original guidance, thereby leading to low RCP material. To ensure adequate nitrogen is removed during reconstitution, adoption of the manufacturer's revised method, involving the deliberate introduction of air, is therefore appropriate.

Effect of experimental conditions on the in vitro stability of99mTc (Sn)-pyrophosphate

The in vitro stability of99mTc (Sn)-PyP as a function of experimental conditions of the preparation of the kit and time elapsed after labeling has been tested. The preparation was protected by using nitrogen-purged reactant solutions and kit vials and by ascorbic acid. The samples under nitrogen are stable for 6 h when the content of99mTc-pertechnetate raises to 5%. The best stability was achieved by addition of 5 μg of ascorbic acid per ml of the kit (content of99mTc-pertechnetate about 0.5%). To accelerate the decomposition, exogenous hydrogen peroxide was used. In this case it was found that the presence of 10 μg of ascorbic acid inhibits the effect both of oxygen and peroxide (6 μg H2O2/ml of the kit). Radiochemical purity of99mTc (Sn)-PyP remains practically unchanged for 6 h (content of99mTc-pertechnetate about 0.5%).

Comparative study of renal scintigraphy with 99Tcm-mercaptoacetyltriglycine and 123I-orthoiodohippurate

This study was undertaken to compare image quality, renal handling and plasma clearance of 99Tcm-mercaptoacetyltriglycine (99Tcm-MAG3) with those of 123I-orthoiodohippurate (123I-OIH). 99Tcm-MAG3 was prepared in-house using an instant kit vial and 123I-OIH was commercially available in a form already labelled. Both studies were undertaken in 20 patients with nephrourological disorders after intravenous (i.v.) injection of 300 MBq 99Tcm-MAG3 and 34 MBq 125I-OIH within the time interval of 3 to 4 days. 99Tcm-MAG3 was much superior to 123I-OIH in visualization of renal perfusion, renal parenchyma and urinary tract. The time parameters of the renogram, Tmax and T1/2 were significantly prolonged in 99Tcm-MAG3 compared to those for 123I-OIH (P < 0.05). Plasma clearance of 99Tcm-MAG3 was also slower than that of 123I-OIH but correlated well with that of 123I-OIH (r = 0.958, P < 0.01). The % renal uptake of 99Tcm-MAG3 per injected dose, which was calculated by the gamma camera method, also correlated well with effective renal plasma flow (ERPF) calculated by the single blood sampling method (r = 0.940, P < 0.01). The renal handling and plasma clearance of 99Tcm-MAG3 are not completely identical with those of 123I-OIH. However, 99Tcm-MAG3 has the clinical advantages of superior image quality, the feasibility of gamma camera measurement of quantitative renal uptake, and ready availability for routine clinical use.