Radiopharmaceuticals

[Audio] My greating to one and all me omkar anandkar from first year pharm D Today we are going to study about radiopharmaceuticals ..

[Audio] The radioactivity The phenomenon of spontaneous emission of certain kind of invisible radiation by some substance is called radioactivity. The radioactive substance used in diagnosis and treatment of some disease like cancer are called radiopharmaceuticals. As we see in the image the radionuclide is linked to target molecule and treats cancer cell ..

What are radioactive substance ?. Radioactive substances have a property of emitting rays or particles which affect the photographic plate. Forty radioactive element are known which are arranged as Uranium series ,thorium series and actinium series..

The radiations or rays which are emitted are follow. they are of 3 type alpha rays beta rays gamma rays

Alpha rays. These rays or particles have low penetrating power.

During emission of an alpha particle atom number decreases by 2 units and mass number decrease by 4 units.

Beta rays. These have 2 type. 1 electrically positive charged particle which are called positrons.

During the emission of beta particle atomic number increases by 1 unit and there is no change in the mass number.

Gamma rays. These have been more penetrating then alpha and beta rays.

The quantity of the radioelement which disappears in units c rate of disintegration is directily proportional to the amount present.

The unstable atom have some chemical and properties as parent element but different kinetic properties.

Radioisotopes. There are 2 types of radioisotopes.

Radioactive Decay Constant. Lamda-is the decay constant No is the number of atoms of radioactive element orignally present N is the number of atoms of the same radioactive element present at time t.

Half life. Time required for a radioactive isotope to decay to one half of its initial value ..

The reciprocal of the radioactive constant or decay constant is called average half life period it is denoted by [tau] T.

The reciprocal of the radioactive constant or decay constant is called Average half life period..

The S.I unit of bacqueral [Bq] .. Curie[c] : Radioactive substance which undergoes the same number of disintegration in time as of 1 gm of radium and is equal to 3.7*10>10 disintegrations per second ..

Units of Radioactivity. The Becquerel (Bq): Disintegration per second, dps.

Radioactivity. The phenomenon of sponteaneous emission kind of invisible radiation by certain substance is called radioactivity. The substance which emits such radiation is called Radioactive substance. It was discovered accidentally by the French Scientist Henry Becquerel..

Uses of Radioactive substance. Radiopharmaceutical are used in medicines. It is used to tret cancerous tumors, to diagnose thyroid disorders and other metabolic disorders disorders including brain function ..

PACKAGING,TRANSPORTATION AND STORAGE OF RADIOACTIVE MATERIALS.

Types of Packaging. The most effective way to reduce the risk associated with transporting radioactive materials is to follow the appropriate packaging standards specified by DOT and, when required, NRC or DOE regulations. The type of packaging used is determined by the activity, type, and form of the material to be shipped. Depending on these factors, radioactive material is shipped in one of three types of containers..

Type A Packages. Radioactive materials with higher specific activity levels are shipped in Type A packages. These packages must demonstrate their ability to withstand a series of tests without releasing the contents. Regulations require that the package protect its contents and maintain sufficient shielding under conditions normally encountered during transportation. Typically, Type A packages are used to transport radiopharmaceuticals (radioactive materials for medical use) and certain regulatory qualified industrial products..

Type B Packages. Radioactive materials that exceed the limits of Type A package requirements must be shipped in Type B packages. Shippers use this type of package to transport materials that would present a radiation hazard to the public or the environment if there were a major release. For this reason, a Type B package design must not only demonstrate its ability to withstand tests simulating normal shipping conditions, but it must also withstand severe accident conditions without releasing its contents..

Package Testing. Radioactive materials are packaged according to their form, quantity, and concentration. DOE ensures that when radioactive materials are transported, they are packaged carefully to protect the public, transportation workers, and the environment. DOT and NRC regulate the testing of radioactive material package designs. DOT is responsible for specifying the required test conditions for packages. NRC certifies that packages designed for materials with higher levels of radioactivity, such as spent fuel, meet DOT’s test requirements..

TRANSPORTATION. Radioactive materials are shipped safely every day. DOE regulations covering these materials strictly control the types that can be carried, their quantities, and the packaging. In addition hazard communication standards help ensure that those who handle or come into contact with these materials – including emergency responders – will be able to identify the cargo and understand the hazards..

Uranium ores: associated chemical products are shipped form mines and mills to purification processors. Irradiated material is shipped to manufacturers of metal and ceramic fuel assemblies..

Measurement of radioactivity. Radioactivity of an element is measure in term of dps ( disintegrate per second ) which is rate at which an element radioactive nulcei disintegrate..

Ionisation chamber. An ionisation chamber consist of chamber filed with gas and fitted with two electrodes kept at different electrical potentials and a measuring device to indicate the flow of electric current . The fill gas can be Ar , He air ,etc . These are available in various size and shape . They have poor resolution due to large number of charge carries . They are operated in current mode..

Proportional counters. If the electric field gradient between the anode and cathode is increased by increasing the applied voltage the electrons produced in the primary ionisation further ionisation the gas molecule eg. The number of ion pair is multiplied. For each primary electron liberated, a large number of ions number of additional electrons are liberated the current pulse through electrical current is greatly amplified . In a certain original number of ion pairs. Proportional counters operate in this voltage region. They are usually operated in pulse mode and are used in the form of gas filled or gas flow counters for a, b, and fission frequent counting . The most forms of common filed pass is P-10 consisting of 90% Ar and 10% methane . The energy resolution of the proportional counter is the range of 5-10%..

Geiger-Muller counter. It is one of the oldest radiation detector types in existence having been introduced by Geiger and muller in 1928 . It is referred to as G-M counter or similar tube . The simplicity , low cost and of ease of operation of these detectors of have lead to their continued use to the present time. They can detect Alpha , Beta, and gamma, radiation ..

Geiger-Muller counter. Metal tube Mica window Wire GEIGER-MULLER COUNTER O .com.

Major Uses of Radioisotopes. Ce-141 Ga-67 Ga-68 P-32 1-125 1-131 Sr-8S Tc-99m Half-Life 32.5 days 78 hr 68 min 4.3 days 60 days 8 days 65 days 6 hr Medical Application Gastrointestinal tract diagnosis; measuring blood now to the heart A bdominal imaging; tumor detection Detect pancreatic cancer Treatment of leukemia. excess red blood cells, pancreatic cancer Treatment of brain cancer; osteoporosis detection Imaging thyroid; treatment of Graves' disease, goiter, and hyperthyroidism; treatment of thyroid and prostate Detection of bone lesions; brain scans Imaging or skeleton and heart muscle, brain. liver. heart. lungs, bone. spleen. kidney, and thyroid; most widely used radioisotope in nuclear medicine Copyrigt* 0 2005 Pearson Educati€v•. rublishirw as Benjamin Cummings.

Storage, handling and precautions. 1. Shelding – radioactive materials should be stored in lead lined containers to minimize exposure to harmful radiation..

IMPORTANT PRECAUTIONS THAT SHOULD BE TAKEN WHILE HANDLING RADIOACTIVE MATERIALS:.

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