Radiopharmaceuticals are radioactive pharmaceutical agents used for diagnostic or therapeutic procedures. They consist of a carrier molecule and a radionuclide. Common isotopes used include iodine-131, technetium-99m, cobalt-57, cobalt-60, gold-198, and iodine-125. Radiopharmaceuticals allow non-invasive monitoring of biological processes through imaging techniques. They are produced in specialized facilities and handled with precautions due to their radioactivity, requiring shielding and controlled storage conditions. Clinical applications include diagnosis of thyroid function and cancer treatment through targeted radiation exposure.

1. RADIO
PHARMACEUTICALS
Definition, Isotopes, Radioactive decay particles, Half life,
precaution, Application, Preparation, Clinical use,

2. Definition
 Radiopharmacy –branch of pharmacy that deals with
radiopharmaceuticals.
 Radiopharmaceutical- a radioactive pharmaceutical agent that is
used for diagnostic or therapeutic procedures
 A radiopharmaceutical consists of a drug/ chemical component(
carrier) and a radioactive component (radionuclide)
 Some carriers such as peptides and monoclonal antibodies are
more specific and are used to target tumor sites-
◦ a desired localization property useful in radio-immunotherapy
◦ Reference

3. Background
 Currently over 100 radiopharmaceuticals available worldwide
◦ radio-nuclides mostly produced from nuclear reactors and cyclotrons
 Radiopharmaceutical production involves handling of large
quantities of radioactive substances and chemical processing
 Radiopharmaceutical production
◦ relatively small scale
◦ requires well qualified personnel
◦ uses controlled materials and procedures
 procedures are technically demanding to ensure both radiological
and pharmaceutical safety.

4. Background
 The radioactivity in radiopharmaceutical allows non-invasive
external monitoring or targeted therapeutic irradiation with very little
effect on the biologic processes in the body
 Imaging techniques e.g gamma camera are then used to monitor
activity
 Generally , radiopharmaceuticals have an excellent safety record
and their incidences of adverse effects is extremely low.

5. Isotopes

6. Isotopes
 Isotopes are variants of a particular chemical element which differ
in neutron number, and consequently in nucleon number.
All isotopes of a given element have the same number of protons
but different numbers of neutrons in each atom.

7. Radioactive decay particles
 Radioactive decay occurs when an unstable atomic nucleus loses
energy by emitting energy in the form of emitted particles or
electromagnetic waves, called radiation.
 In natural radioactive decay,
three common emissions occur.
 alpha particles (αα),
 beta particles, (β)(β), and
 gamma rays (γ)(γ)

8. Radioactive decay particles

9. Units of radioactivity
 SI unit: becquerel (Bq)
 One Bq is defined as one transformation (or decay or
disintegration) per second.
 Other units:
 curie, Ci, which was originally defined as "the quantity or
mass of radium emanation in equilibrium with one gram
of radium (element)
 1 curie (Ci) = 3.7×1010 Bq

10. Radioactive decay rates
 Half Life
 Decay constant
 Mean life time
 The half-life—t1/2, is the time taken for the activity of a
given amount of a radioactive substance to decay to half
of its initial value;

11. Radioactive decay rates
 Half Life
 Decay constant
 Mean life time
 The half-life—t1/2, is the time taken for the activity of a
given amount of a radioactive substance to decay to half
of its initial value;

12. Handling of Radio pharmaceuticals
 Great care needs to be taken in handling and storage of radioactive materials for protecting people
and personnel who handle it, from the harmful radiation they emit.
 Certain precautions have to be taken while working with detectors, tracer equipment, radio assay
manufacturing or handling of radioactive materials.
 In order to have protection from hazards of radiation, radioactive materials must be stored in an
area not frequently visited by people.
 Shielding may be required.
 Thick glass or Perspex containers provide sufficient shielding.
 To protect from gamma rays (high penetration power), lead shielding has to be used.
 The storage area must be regularly checked for radioactivity.
RADIOACTIVE LIQUIDS.
 Working area should not get contaminated with radioactive material.
 If radioactive liquid is to be handled, it must be carried in trays with absorbent tissue paper, so that
any spillage will get absorbed by the paper.

13. Storage of Radio pharmaceuticals
 Radiopharmaceuticals should be kept in well-closed
containers and stored in an area assigned for the
purpose. The storage conditions should be such that the
maximum radiation dose rate to which persons may be
exposed is reduced to an acceptable level. Care should
be taken to comply with national regulations for protection
against ionizing radiation.
 Radiopharmaceutical preparations that are intended for
parenteral use should be kept in a glass vial, ampoule or
syringe that is sufficiently transparent to permit the visual

14. Radiopharmaceutical
 A Radiopharmaceutical is a drug that can be used
either for diagnostic or therapeutic purposes. It is
composed of a radioisotope bond to an organic
molecule. The organic molecule conveys the
radioisotope to specific organs, tissues or cells.
 Radioactive element - 133Xe
 Labeled compounds - 131I iodinated proteins

99mTc labeled compounds
 [18F]FDG

15. Idea Properties of
Radiopharmaceutical
• Easy availability
• Short effective Half-Life
• Particle Emission
• Decay by Electron Capture or Isomeric Transition
• High Target-to Nontarget Activity Ratio

16. Type of radiopharmaceutical
for diagnostic and therapy
 Parenteral pharmaceuticals (solutions or colloid
suspenses),
 peroral pharmaceuticals
 inhalation pharmaceuticals
 topical pharmaceuticals

17. USE
 Radioisotopes in Therapy (Emitted radiations used to
destroy cells in condition like cancer)
 Radioisotopes in Diagnosis (Radioactive tracers)
 Research (Biological and medicinal studies by use of
radioactive isotopes as tracers)
 Sterilization (For sterilization of pharmaceuticals and
surgical instruments)

18. Clinical Application
 Therapeutic radiopharmaceuticals are designed to deliver
therapeutic doses of ionising radiation to specific diseased sites for
curative or palliative purposes by destruction of diseased tissues
 May be used internally as tissue implants in sealed capsules
(mainly used in radiation oncology)or externally as unsealed
administered orally, intravenously (IV) or placed directly into a body
cavity (such as a knee joint) or peritoneum.

19. Radionuclide ( halflife) Application
Radioimmunotherapies:
•I-131 Tositumomab; Y-90
Ibritumomab; Y-90
epratuzunab
Non-Hodgkins
Lymphoma
Americum 241, Californium
252, Cobalt 60, Gold -194
Cancers and tumours
Holmium 66( 26 hr) Liver cancers
Iodine 131 ( 8.1 days) Antineoplastic , Grave’
disease (hyperthyroidism
and differentiated thyroid
cancer .
Rhenium 186( 3.8 day),
Samarium 153(47 hr)
Strontium 89
Pain relief in bone
cancer; Pain relief in
bone cancer, prostate
and breast cancer
Reduces Pain in Prostate
& bone cancer

20. Uses of Cobalt -57 & 60
 Co 57- Diagnosis of pernicious anemia – cynocobalamine
 Cynocobalamine solution: Co 60- Absorption and deposition of Vit
B12

21. Uses of Gold – 198
 Estimation of recticulo endothelial activity

22. Uses of Iodine- 125 & 131
 Used as a diagnostic aid for studying the functioning of the thyroid
gland.
 Used in scanning the thyroid for determining the size, position and
possible tumour location.
 Used in the treatment of severe cardiac disease (Sodium iodide I-
131), which reduces work load on heart.
 Radioactive iodine in thyroid carcinoma (cancer): The isotope is
used most frequently after the surgical removal of cancer to treat
any residual tumour tissues.