Radiopharmaceuticals are produced through three main methods: nuclear reactors, cyclotrons, and isotope generators. In nuclear reactors, fission or neutron activation produces radioactive isotopes. Cyclotrons bombard targets like sodium-23 with particles to make radioactive isotopes deficient in neutrons. Isotope generators contain a long-lived parent isotope that decays to a short-lived daughter isotope, like molybdenum-99 decaying to technetium-99m, which is then eluted for medical use.

1. INTRODUCTION
Radiopharmaceuticals

2.  Atomic number
 Mass number
 Isotopes
-stable isotopes
-unstable isotopes
 Radio-active halflife
 Units of Radio-activity
-Roentgen
-RAD
-REM
-Becquerel(bq)

3. METHODS OF PRODUCTION
 PILE PRODUCED ISOTOPES (NUCLERA
REACTOR)
 CYCLOTRON – PRODUCED ISOTOPES
 RADIO ISOTOPES GENERATOR

4.  Most of the R-A materials prepared in nuclear
pile
 Uranium fission rxn produces large supply of
neutrons
 Neutrons in rxn are a mixture of fast
neutrons and thermal
 Thermal neutrons are obtained by fast
neutrons thru a moderator
 n γ Rxn . Target nuclie captures thz thermal
neutron to yield a radioactive nucleus in an
excited state
 Surplus energy emitted as γ-radiation

5.  Eg. 2311Na +n 23 Na
14
23 Na +γ
14
1 neutron for each uranium atom undregoes
fission and other neutrons are used to produce
PLUTONIUM by interaction with 238U
 These neutrons are either lost or used to
interact with specific target which have been
inserted into “neutron activation”
1. Radio-active material thru Fission process
2. Radio-active material thru Neutron activation
FISSION Reactions :
238
92 U+ 10n 131
50 Sn + 10642 Mo + 10n+ 1
0n
131
50 Sn and 10642 Mo are radio active nuclides

6. NEUTRON ACTIVATION
When simple neutron is captured or during
transmutation process neutron activation occurs
a radio-activated phosphorus, 32P can be
prepared from stable phosphorus , 31p by
neutron capture

7.  Radio-activewhich are neutron deficient are
produced by cyclotron
 Obtained by bombarding targer nuclie with
protons deuterons α particle

11.  During investigation , hazards to patients can
be reduced by using isotopes
 Such isotope can be supplied in form of long
lived parent that decay to isotope required
 Parent nuclide prepared in form of suitable
ion – absorbed to the ion exchange column
 The whole assembly is known ass Radio-
isotope generator
 This long lived parent results in production
short lived daughter
 Whicj is “eluted” or “milked” from column

12.  Eg. Technetium 99m
 99m Tc generator sonsist of column containing
alumina on which Molybdenum 99 is absorbedin
form of ammonium molybdate
 Radioactive decay of 99 Mo produces 99mTc
which is eluted from the column
 This isotope is produced for brain , liver and in
thyroid scanning and is safer
 It has short life and does not emit beta
radiations.