NUCLEAR PHARMACY AND RADIOPHARMACEUTICALS

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1. Nuclear Pharmacy
In a nuclear pharmacy radiopharmaceuticals are prepared, stored, and dispensed primarily for human use, just as regular drugs are in a pharmacy. The nuclear pharmacy is staffed with trained personnel such as radiopharmacists and radiochemists, that is, chemists or pharmacists with special training in radiopharmaceutical chemistry. The nuclear pharmacy may serve as a center for education and training of pharmacy and nuclear medicine technology students and engage in basic research in the design and development of new radiopharmaceuticals. Here the remedy for any adverse reaction in humans due to the administration of radiopharmaceuticals is sought and found. The nuclear pharmacists can provide education and consultation to the patients and health care personnel in this field.

1.1 Design of a Nuclear Pharmacy
Several common problems should be kept in mind when designing a nuclear pharmacy unit. Protection of personnel from radiation hazard, avoidance of contamination of work area and radiation-detection instruments, clean air circulation in the dispensing area, and disposal of radioactive waste are the common concerns. The design of a nuclear pharmacy should take into account daily operational protocols, proper utilization of available space,and provisions for future growth. A nuclear pharmacy should be located within or near the nuclear medicine department because there is a close relationship between the two units. The nuclear pharmacy area can be as small as a 12 Х 12 ft (4m Х 4m) room, depending on the volume of the operation. For a larger operation, the unit may consist of several rooms. Ideally, it should have enough space for accommodating offices, a counting room, and a health physics laboratory on one side of a corridor, and a high radiation (hot lab) laboratory, a compounding room, a storeroom, and a dispensing area on the other side. [1]


. Definition of a Radiopharmaceutical
A radiopharmaceutical is a radioactive compound used for the diagnosis and therapeutic treatment of human diseases. In nuclear medicine nearly 95% of the radiopharmaceuticals are used for diagnostic purposes, while the rest are used for therapeutic treatment. Radiopharmaceuticals usually have minimal pharmacologic effect, because in most cases they are used in tracer quantities. Therapeutic radiopharmaceuticals can cause tissue damage by radiation. Because they are administered to humans, they should be sterile and pyrogen free, and should undergo all quality control measures required of a conventional drug


Ideal Radiopharmaceutical
The ideal characteristics for radiopharmaceuticals are elaborated below.
• Easy Availability
The radiopharmaceutical should be easily produced, inexpensive, and readily available in any nuclear medicine facility. Complicated methods of production of radionuclides or labeled compounds increase the cost of the radiopharmaceutical.

• Short Effective Half-Life
It is the time needed for half of the radiopharmaceutical to disappear from the biologic system and therefore is related to a decay constant, lb ¼ 0:693=Tb. The physical half-life is independent of any physicochemical condition and is characteristic for a given radionuclide.

• Particle Emission
Radionuclides decaying by a- or b-particle emission should not be used as the label in diagnostic radiopharmaceuticals. These particles cause more radiation damage to the tissue than do gamma rays. But α and β emitters are useful for therapy, because of the effective radiation damage to abnormal cells.

• Decay by Electron Capture or Isomeric Transition
Because radionuclides emitting particles are less desirable, the diagnostic radionuclides used should decay by electron capture or isomeric transition without any internal conversion. Whatever the mode of decay, for diagnostic studies the radionuclide must emit a g radiation with an energy preferably between 30 and 300 keV. Below 30 keV, g rays are absorbed by tissue.