Page 202 - Pharmaceutics IV (02-06-01305)

Radiopharmaceuticals

e.g. Technetium -99m ( 99m Tc ),gold (198 Au ),iridium (192 Ir
),phosphorus (32 P as sod. Phosphate),Yttrium (90 Y ), Iodine ( 131 I
as sod. Iodide ) & Pallidium (103 P ).

Examlpe of Radioisotopes :

1- Technetium -99m (99m Tc )
Short t1/2 allow administration of higher amounts of activity for
faster & cleaner images while exposing the patient to a low
radiation dose .It offers gamma photons for imaging without the
hazardous effects of beta particles. Its chemistry profile is
flexible which allows it to be used as a binding agent for several
pharmaceuticals used for imaging. Kits are available for
hepatobiliary imaging & ischemic heart disease.

2-Colloidal Gold (198 Au ) :

Suspensions have been used in the cases of fluid accumulation

In the abdomen ( peritoneal cavity ) or chest (plural cavity )
associated with malignant tumors. Colloidal suspensions diffuses
throughout the fluid & ,over time <tends to aggregate at the
surface of the cavity.

3- Nylon ribbons containing Iridium ( 192 Ir ):

Seeds at periodic intervals can be implanted into the interstitial
cavity for the treatment of tumors .These ribbons are surgically
removed.

4- Radiophosphorus ( 32 P )

Can be injected parenterally as a solution of a highly soluble sod.Salt.
It tends to accumulate in rapidly proliferating cells & tissues.

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