TECHNICAL FIELD

The presently-disclosed invention relates generally to metal-molybdate materials suitable for use in technetium-99m generators (Mo-99/Tc-99m generators) and methods for making the same.

BACKGROUND OF THE INVENTION

Technetium-99m (Tc-99m) is the most commonly used radioisotope in nuclear medicine (e.g., medical diagnostic imaging). Tc-99m (m is metastable) is typically injected into a patient which, when used with certain equipment, is used to image the patient's internal organs. However, Tc-99m has a half-life of only six (6) hours. As such, readily available sources of Tc-99m are of particular interest and/or need in at least the nuclear medicine field.

Given the short half-life of Tc-99m, Tc-99m is typically obtained at the location and/or time of need (e.g., at a pharmacy, hospital, etc.) via a Mo-99/Tc-99m generator. Mo-99/Tc-99m generators are devices used to extract the metastable isotope of technetium (i.e., Tc-99m) from a source of decaying molybdenum-99 (Mo-99) by passing saline through the Mo-99 material. Mo-99 is unstable and decays with a 66-hour half-life to Tc-99m. Mo-99 is typically produced in a high-flux nuclear reactor from the irradiation of highly-enriched uranium targets (93% Uranium-235) and shipped to Mo-99/Tc-99m generator manufacturing sites. Mo-99/Tc-99m generators are then distributed from these centralized locations to hospitals and pharmacies through-out the country. Since the number of production sites are limited, and compounded by the limited number of available high flux nuclear reactors, the supply of Mo-99 is susceptible to frequent interruptions and shortages resulting in delayed nuclear medicine procedures.

There at least remains a need, therefore, for a process for producing material suitable for use in technetium-99m generators (Mo-99/Tc-99m generators).

SUMMARY OF INVENTION

One or more embodiments of the invention may address one or more of the aforementioned problems. Certain embodiments according to the invention provide a process for producing a metal-molybdate (also referred to herein as metal-Mo), such as a metal-Mo material suitable for use in technetium-99m generators. The term “metal-molybdate”, as used herein, generally refers to either a metal-molybdate, metal-molybdenum, molybdenum-metalate, or any form of Mo-metal or metal-Mo species. Processes according to certain embodiments of the invention may comprise reacting a metal molybdenum (Mo) material in a liquid medium (e.g., an aqueous medium) with a first acid (e.g., a mineral acid) to provide a Mo composition and combining the Mo composition with a metal source to provide a metal-Mo composition. Processes according to certain embodiments of the invention may further comprise pH adjusting the metal-Mo composition with a base (e.g., ammonium hydroxide) to precipitate a plurality of metal-Mo particulates (also referred to herein interchangeably as particles). In accordance with certain embodiments of the invention, the metal-Mo particulates may be isolated from or separated from the liquid medium. In accordance with certain embodiments of the invention, the isolated metal-Mo particulates may take the form of a slurry including a residual amount of the liquid medium therein. The isolated metal-Mo particulates may be subjected to heat energy to at least partially dry the metal-Mo particulates. The metal-Mo particulates may be milled and washed. In accordance with certain embodiments of the invention, the processes may comprise irradiating a metal molybdenum target to provide the Mo material as discussed herein. That is, the step of irradiating a metal molybdenum target to provide the Mo material may be carried out prior to the combination of the metal Mo material in a liquid medium with the first acid. The metal molybdenum target, for example, may comprise a tubular capsule comprising metal molybdenum and a plurality of internal metal molybdenum components (e.g., balls, rods, wires, discs, etc.) housed inside of the tubular capsule. Alternatively, the metal molybdenum target, for example, may be one or more metal molybdenum components (e.g., balls, rods, wires, discs, etc.) used alone or in combination, such as a rod with a series of discs. In this regard, certain embodiments of the invention comprise a metal-Mo material produced according to processes disclosed herein.

In some embodiments of the invention, an intermediate product may be present for further processing if so desired.

In yet another aspect, the invention provides the metal-Mo material comprises a plurality metal-Mo particulates.

In accordance with certain embodiments of the invention, the process may comprise irradiating the resulting metal-Mo material comprising a plurality of metal-Mo particulates. For example, the irradiation may be carried out prior to loading the metal-Mo particulates into an elution vessel.

In accordance with certain embodiments of the invention, the metal-Mo material comprises an eluting efficiency of 30% or greater, an eluting efficiency of 80% or greater, 90% or greater, or 95% or greater. The metal-Mo material, in accordance with certain embodiments of the invention, may be disposed in an elution column (e.g., technetium-99m generator) and at least 90% (e.g., at least 95% or at least 99%) of a total technetium content releases from the metal-Mo material via passing an aqueous liquid (e.g., water, saline, dilute acid) through the metal-Mo material.

Other embodiments of the invention are described herein.

