RADIOPHARMACEUTICALS-I PHARM.D-PHARMACEUTICAL INORGANIC CHEMISTRY

1. RADIO PHARMACEUTICALS
Kencha swathi
Assistant professor
ABIPER
BANGALORE

2. INTRODUCTION
 Radiopharmaceuticals are the radioactive
substances or radioactive drugs for diagnostic or
therapeutic interventions.
 A radioactive isotope can be injected safely into
the body and a carrier molecule which delivers
the isotope to the area to be treated.
 Alpha rays(α-rays):These rays or particles have
the least penetrating power , positive charge and
have a strong imagistic field.

3.  Beta rays ( β- rays): They have greater
penetrating power than that of alpha rays.
 β- rays are of two types –
(i)Electrically positive particles (positrons)
(ii)Electrically negative particles( negatrons)
 Gamma rays(γ-rays): These have praoduced
during nuclear fission. More penetrating than
alpha & beta rays.

4. ISOTOPES
 Nuclides having the same number of protons but
different number of neutrons are termed as
isotopes.
 Radioisotopes have been those that undergo
nuclear changes or rearrangements that cause the
emission of radiation.

6. MEASUREMENT OF RADIO ACTIVITY
 To measure the radiations of alpha,beta and
gamma particles, many techniques involving
detection and ounting of individual particles as
photons are available.
 The method selected for the measurement of
radioactivity depends upon the extent of energy
dissipation and penetrability of radiation.

7. The Techniques are :
1.Ionisation chambers
2.Proportional counters
3. Geiger-Muller counters
4.Scintillation method especially for
counting gamma radiations.
5.Autoradiography
6. Solid state detectors

9. APPLICATIONS

10. CLINICAL APPLICATIONS
Radioisotopes are used in Therapeutics:
 Gold (¹⁹⁸Au ) is used in the treatment of abdominal
effusion associated with malignant tumour,Carcinoma of
uterus and urinary bladder.
 Sodium phosphate (³²P) is used to treat polycythemia
(decrease the rate of formation of RBC) & leukemia.
 Cobalt labelled cyanocobalamins(Co-57,C0-58,Co-60)
used in the diagnosis of pernicious anaemia.
 Sodium iodide (¹³¹I) used in the treatment of thyroid
disorders.

11. Radioisotopes in Diagnosis:
 Ferric citrate(⁵⁹Fe) injetion is used for the
diagnosis of haematological disorders.
 Sodium iodohippurate I-131 injection is used for
the diagnosis of renal functions.
 Iodine( ¹³¹I) serum albumin injection used to
identify the cardiovascular functions.

12.  Radioisotopes are used in research.
 Sterilization: Radiopharmaceuticals are used for
sterilizing final packed containers and surgical
instruments in hospitals.
 Radioactive calcium(Ca-44 & Ca-45) are used to
study bone structure and for the treatment of
carcinoma of bone.
 Cobalt-60 is used for the sterilisation of surgical
materials and dressings by the gamma radiations.
 Radioactive isotopes of cyanacobalamin used to
study the absorption and deposition of vitamin B₁₂
in normal individuals.
 Gold( Au-198) solution is used in estimation of
reticuloendothelial activity

13.  Hydrogen(H-2 & H-3) are useful to determine
total body water.
 Iron(Fe-59) used to measure RBC life span
and iron metabolism
 Radioactive chromium-Sodium chromate( Cr-
51) is used to study red cell volume and
survival time.
 Iodine(¹³¹I) is used in the treatment of
hyperthyroidism and hypothyroidism.
 ¹³¹I is used in the destruction of thyroid
follicles due to β-particles and surgical
removal of thyroid gland.

15. DOSAGE OF RADIOPHARMACEUTICALS
 Proper dosages are derived through careful study of
pharmacokinetics,physical characteristics of
radionuclide,metabolism of subject,pharmacodynamics of the
radiopharmaceutical of the subject.
 The chemical and radiotoxicities and adverse reactions are well
understood before an optimal and safe dosage is recommended.
 Doses are typically scaled by weight, or total body surface area,
and reduced for children.
 The recommended dosage for a specific indication and route of
administration are stated by the drug manufacturers in the package
insert, and are readily available online.

16. DOSAGE

18. HAZARDS
 Allergies
 Pregnancy – Radiopharmaceuticals are not
recommended for use during pregnancy to avoid
exposure of foetus to radiation.
 Thyroid damage – Radioactive iodine enters into
the baby’s thyroid gland during pregnancy in high
amounts and causes thyroid damage.
 Breast feeding – Radiopharmaceuticals pass into
the breast milk and expose the baby to radiation.
 Children – Low amount of radiopharmaceuticals
are used in children and diagnosed safely.

19. PRECAUTIONS

20. THANK YOU