Radiopharmaceuticals PPT PDF

Radiopharmaceuticals-V  Dr Shashank Tewari  SODIUM IODIDE (I-131) ❑ Sodium iodide which contains radioactive I-131 isotope is a radiopharmaceutical substance that is mainly used to treat the malignancy of the thyroid gland. ❑ It is available in various p...

Radiopharmaceuticals-V  Dr Shashank Tewari  SODIUM IODIDE (I-131) ❑ Sodium iodide which contains radioactive I-131 isotope is a radiopharmaceutical substance that is mainly used to treat the malignancy of the thyroid gland. ❑ It is available in various pharmaceutical formulations such as in solution, capsule, or injection forms. ❑ The sodium iodide molecule gets dissociated due to ionization and emit two different types of radiation i.e. β (90%) and γ (10%) radiations.  SODIUM IODIDE (I-131) Mechanism of action ❑ All the radioactive isotopes of iodide are easily trapped by the thyroid gland via sodium/iodide symporter and then oxidized into iodine and then it emits β and γ- radiations. ❑ The beta radiations (90%) destroy the malignant cells of thyroid tissue. ❑ Therefore, the radioactive iodine destroys the abnormal cells of the thyroid gland by passing radiation through it.  SODIUM IODIDE (I-131) Properties: ❑ The sodium iodide solution is clear and colourless. But after a certain time interval, it may be darkened due to the effects of radiation emitted by the radioisotope. ❑ The pH of its aqueous solution is between 7.5 to 9.0. But in the injection formulation of sodium iodide, a preservative (benzyl alcohol) and reducing agent (sodium thiosulfate) are added to increase their shelf-life and prevent their oxidation in an aqueous solution. ❑ The half-life of 131I is 8 days. It emits both the β and γ-rays.  SODIUM IODIDE (I-131) Assay: ❑ The assay of sodium iodide is performed by comparing the activity of radioactive sodium iodide with standard I131 solution. ❑ As we already discuss that I131 radioisotope emits both β and γ-rays. ❑ The radioactivity should be recorded with a Geiger-Muller counter or scintillation detector. ❑ Dose The dose of sodium iodide 131I is from 5 to 1000 µCi. ❑ It also depends upon the procedure being performed.  SODIUM IODIDE (I-131) Uses ❑ In small doses, it is used to detect the normal functioning of the thyroid gland. ❑ In high doses, it is used in the therapy of thyroid gland malignancy. ❑ It is also used to cure hyperthyroidism.  SODIUM IODIDE (I-131) Uses ❑ In small doses, it is used to detect the normal functioning of the thyroid gland. ❑ In high doses, it is used in the therapy of thyroid gland malignancy. ❑ It is also used to cure hyperthyroidism. Common Side effects Nausea Vomiting Tenderness and swelling in the neck Dry mouth Loss of taste SODIUM IODIDE (I-131) SODIUM IODIDE (I-131)  Storage Conditions of Radiopharmaceuticals ❑ Radioactive substances should be stored in well-closed tight containers. ❑ It should be stored in such a place where there is a restriction on the frequent visits. ❑ The storage area of radioactive compounds should be organized in such a manner that it meets all the guidelines as per national and international regulations. ❑ The containers of radiopharmaceuticals should be labelled properly to avoid misuse and adverse effects. ❑ During storage, the container may be darkening due to the emission of radiation. It does not mean the radioactive substance is degraded. ❑ The radioactive substance for parenteral use must be kept in a glass vial or ampoule to clearly visualize the content.  Storage Conditions of Radiopharmaceuticals ❑ Radioactive substances should be stored in well-closed tight containers. ❑ It should be stored in such a place where there is a restriction on the frequent visits. ❑ The storage area of radioactive compounds should be organized in such a manner that it meets all the guidelines as per national and international regulations. ❑ The containers of radiopharmaceuticals should be labelled properly to avoid misuse and adverse effects. ❑ During storage, the container may be darkening due to the emission of radiation. It does not mean the radioactive substance is degraded. ❑ The radioactive substance for parenteral use must be kept in a glass vial or ampoule to clearly visualize the content.  PHARMACEUTICAL APPLICATIONS OF RADIOACTIVE SUBSTANCES The radioactive substances can be used in medicine in four different ways: ❑ Radiopharmaceuticals as a therapeutic agent ❑ As diagnostic agents ❑ Research studies ❑ Sterilization Radiopharmaceuticals as a therapeutic agent Radiopharmaceuticals as Diagnostic Agents Radiopharmaceuticals in Research studies  Radiopharmaceuticals in Sterilization Radiations are most widely used in the microbiology lab for the sterilization of culture media. Radiations are also used for the sterilization of surgical instruments in hospitals. And it is used to sterilize thermolabile (degrade after exposure to heat) biological substances such as vitamins, antibiotics, and hormones. Miscellaneous Applications Thank You