Simple new method for labelling of PSMA-11 with 68Ga in NaHCO3

New Approved Drugs Appearing in the Pharmaceutical Market in 2022 Featuring Fragments of Tailor-Made Amino Acids and Fluorine

The strategic fluorination of oxidatively vulnerable sites in bioactive compounds is a relatively recent, widely used approach allowing us to modulate the stability, bio-absorption, and overall efficiency of pharmaceutical drugs. On the other hand, natural and tailor-made amino acids are traditionally used as basic scaffolds for the development of bioactive molecules. The main goal of this review article is to emphasize these general trends featured in recently approved pharmaceutical drugs.

Radiochemical quality control of the radiopharmaceutical, 89SrCl2 produced in FBTR

⁸⁹SrCl₂ radiopharmaceuticals is mainly used for bone pain palliation in the cancer patients, is being produced in FBTR via ⁸⁹Y(n, p)⁸⁹Sr using yttria target. The irradiated yttria target is chemically processed in high pure quartz distilled nitric acid medium in hot cell facility, to avoid the corrosion of components of hotcell due to chloride ions while using HCl medium. Being ionic species, the purified ⁸⁹Sr(II) cation in aqueous solution containing bulk nitrate and other trace anions, exists as SrX_n species where X: F^-, Cl^-, Br^-, NO₃^-, PO₄^3- and SO₄^2-, n: stoichiometric anion content. The aim of the manuscript is to standardise an efficient ultra-low level anion purification method (ppb range) for the conversion of SrX_n to SrCl₂ and estimate the residual anionic impurities as recommended by the appropriate source specifications for its medical application. Various methods were standardised for the removal of anions in the SrCl₂ source produced by the above process which include evaporation, calcination, anion exchange column, cation exchange column as well as its combination with pre-concentration column of ion chromatography (IC) technique using ⁸⁹Sr tracers as well as FBTR produced ⁸⁹Sr solution. Assay of ⁸⁹Sr and other anions including nitrate for the above study were accomplished using Cerenkov counting and ion chromatography respectively. Thus evaporation-calcination-column chromatography mode was finalised to obtain pure SrCl₂ source free from nitrate and other anionic impurities. This is the first ever systematic study for the Radiochemical quality control of nca ⁸⁹SrCl₂ radiopharmaceutical produced in a fast reactor. This study also finds its application to any analytical lab as well as industry where there is a requirement of anion purification in the ppb level.

Kit-based preparation of [68Ga]Ga-P16-093 (PSMA-093) using different commercial 68Ge/68Ga generators

PURPOSE

Prostate-specific membrane antigen (PSMA) is an important biomarker for molecular imaging and a target for radionuclide therapy of prostate cancer. Recently, U.S. Food and Drug Administration (FDA) has approved [⁶⁸Ga]Ga-PSMA-11 as a PSMA-targeted positron emission tomography (PET) imaging agent for the diagnosis of prostate cancer. As an alternative PSMA imaging agent, [⁶⁸Ga]Ga-P16-093 ([⁶⁸Ga]Ga-PSMA-093) showed excellent blood clearance and rapid tumor uptake, desirable in vivo properties for avidly detecting primary tumor and metastatic lesions in patients. To improve the availability and test the robustness of radiolabeling reaction, eluents of ⁶⁸Ga/HCl from different sources of generators were evaluated.

PROCEDURES

Commercially available ⁶⁸Ge/⁶⁸Ga generators from Eckert & Ziegler, ITG and iThemba were eluted with varying molarities of hydrochloric acid (0.05-0.6 M, as recommended by each company) and reacted with P16-093 kits. Radiolabeling yields, in vitro stabilities, in vitro cell uptakes and drug release criteria of different preparations were investigated. PET/computed tomography (CT) imaging of prostate cancer patients with [⁶⁸Ga]Ga-P16-093 produced by using different sources of ⁶⁸Ga were performed.

RESULTS

Optimized P16-093 kit containing 15 μg of P16-093 (precursor) and 68 mg of sodium acetate trihydrate (buffer), a formulation previously tested in humans, was successfully labeled with eluents from Eckert & Ziegler, ITG and iThemba's generators. In vitro cell uptake studies showed that [⁶⁸Ga]Ga-P16-093, formulated with ITG and iThemba's generators, exhibited equivalent PSMA-specific uptakes. Clinical studies in prostate cancer patients exhibited exceedingly comparable maximum standardized uptake value (SUVmax) for each lesion regardless of source of the generator used in preparation.

CONCLUSION

Using different vendors' generator and lyophilized P16-093 kits, [⁶⁸Ga]Ga-P16-093 could be conveniently and reliably prepared by a simple one-step reaction with excellent yields. Clinically useful doses of [⁶⁸Ga]Ga-P16-093 imaging tracer could be made available using different ⁶⁸Ge/⁶⁸Ga generators.

The Pharmaceutical Technology Approach on Imaging Innovations from Italian Research

Many modern therapeutic approaches are based on precise diagnostic evidence, where imaging procedures play an essential role. To date, in the diagnostic field, a plethora of agents have been investigated to increase the selectivity and sensitivity of diagnosis. However, the most common drawbacks of conventional imaging agents reside in their non-specificity, short imaging time, instability, and toxicity. Moreover, routinely used diagnostic agents have low molecular weights and consequently a rapid clearance and renal excretion, and this represents a limitation if long-lasting imaging analyses are to be conducted. Thus, the development of new agents for in vivo diagnostics requires not only a deep knowledge of the physical principles of the imaging techniques and of the physiopathological aspects of the disease but also of the relative pharmaceutical and biopharmaceutical requirements. In this scenario, skills in pharmaceutical technology have become highly indispensable in order to respond to these needs. This review specifically aims to collect examples of newly developed diagnostic agents connoting the importance of an appropriate formulation study for the realization of effective products. Within the context of pharmaceutical technology research in Italy, several groups have developed and patented promising agents for fluorescence and radioactive imaging, the most relevant of which are described hereafter.