Kit Preparation

The preparation of any Tc pharmaceutical is performed by using a commercial cold kit and adding the required Tc activity in a certain volume of Tc eluate (pertech-netate). Kits offer couveuieuce aud ease of preparation for ad hoc labeling. 

Cold kits are considered as semimanufactured products, which ueed marketing authorization as medicinal products (European Economic Community 1998). Cold kits are commonly produced at the industrial level. The preparation of a Tc pharmaceutical by a uuclear mediciue facility or a nuclear pharmacy by adding Tc eluate to an 

---

In the case of Tc pharmaceuticals, chemistry and safety have been compounded into kits, which have overcome the limitations set by radioactive decay and the risk of bacterial contamination. Kits are manufactured in advance in accordance with GMP requirements for the manufacture of sterile medicinal products, have a long shelf life, and facilitate ad hoc labeling whenever there is a demand in nuclear medicine. Kits provide safety and ease of preparation of highly complex molecules by using aseptic techniques for labeling. Consequently, quality control requirements for kit preparations rely merely on testing the radiochemical purity of a " Tc pharmaceutical to demonstrate stability in compliance with the purity requirements stated in the pharmacopeia. 

Labeling procedures have been greatly facilitated by kit preparations (Eckelman et al. 1971). Sterile kits for labeling contain the chemical ingredients in lyophilized form are commercially available and used to prepare " Tc pharmaceuticals shortly before application to the patient. Manipulation is minimal, since all that needs to be done is adding the " Tc activity to the kit. In some cases, heating of the reaction mixture is performed to increase the labeling yield. 

The need for simple labeling methods for Tc pharmaceuticals had been expressed by scientists and physicians as early as 1965. The introduction of stannous ion as a re-ductant for kit preparation offered new perspectives in the development of Tc radiopharmaceuticals and attracted interest of all parties (Alvarez 1975 Eckelman et al. 1971b). 

The behavior of stannous ion in kit preparations has been studied in a limited number of compounds, and the conclusion reached so far indicates that, apparently, tin ions only reduce TcOj and indeed, apart from some tin-essential preparations such as stannous oxide colloid labeled with " Tc (Subramanian and McAfee 1970), mixed Tc-Sn complexes have not been observed in low-molecular-weight radiopharmaceutical preparations. 

Reduced, hydrolized Tc is a colloidal impurity in kit preparations. Depending on the amount present, it may distort the biodistribution pattern and limit the diagnostic value of the Tc pharmaceutical. The biodistribution of Tc-Sn colloid itself was studied separately (Syhre et al. 1976). The authors observed that the liver-to-kidney ratio is highly dependent on the pH of the preparation, reflecting the hydrolytic properties of tin hydroxide. 

The lyophilized formulation is under nitrogen atmosphere to avoid oxidative processes the introduction of air into the vial must be avoided. A breather needle should not be used. It is recommended to use a separate kit preparation for each patient. If... 

Seifert S, Muth 0, Jantsch K, Johannsen B (1995) Radiochemical purity of Tc-HM-PAO critical parameters during kit preparation. Presented at the second COST B3 workshop in Villigen (Switzerland), 6-7 October 1994. Nucl Med Biol 22 1063-1066... 

Radiopharmaceuticals labeled with " Tc are commercially available and are employed in more than 80% of all nuclear medicine investigations. Among the radionuclides, technetium-99m is most attractive to the nuclear medicine physician because of its optimal gamma energy for SPECT, its availability, its relatively low cost, and its easy-to-la-bel kit preparations for in-house use. Another advantage is the low radiation burden to patients, due primarily to its short half-life. The decay within hours also facilitates the handling of waste. 

The presentation of Tc pharmaceuticals as monographs serves a practical purpose it offers relevant information on kit preparation and clinical application at a glance. These monographs provide a wide spectrum of information on Tc pharmaceuticals for daily practice in nuclear medicine, serving as a reference source as well as a teaching tool. 

From this kit, prepare solution A (Galacton-Star , Emerald II , lysis buffer (1 5 19)) and solution A2 (solution A ED (1 1))... 

From this kit, prepare detection reagent mix Galacton-Star, Emerald II, cell assay buffer (1 5 19) protect from hght by wrapping the tube with aluminum foil... 

The most common preparation process is the so-called kit preparation, which comprises the following steps ... 

Finished parenteral products prepared in the radiopharmacy department must be sterile. Based on a risk analysis one may conclude that the risk of non-sterility is very low for standard radiopharmaceutical kit preparations. The risk of contamination is somewhat higher for the eluate from radionuclide generators, especially when they are used for a long period. The injection bottle on top of a Tc generator (sterile sodium chloride solution for injection) is changed asepti-cally each day however, the inside of the generator system is not sterilised nor disinfected. For that reason it is recommended to control the microbiological quality of the... 

---