The therapeutic
properties of some medicinal products are increased when they are formulated in
colloidal state. For example
1. Colloidol
calome (Hg nitrate , gelatin, NaCl) has higher antiseptic activity than in the
coarse powder.
2. Colloidal
Silver chloride (AgCl), Silver Iodide (AgI), and Silver (Ag) proteins are
germicidal which do not cause irritation as their ionic Ag salts.
3. Adsorption
of toxins from GIT by kaolin and the rate of neutralization of excess acidity
in the stomach by Aluminium hydroxide is higher if the compounds are in
colloidal form.
4. Blood
plasma substitutes are colloidal dispersions in which the particle size is big
to allow retention in blood vessels for adequate time (eg dextran inj BP,
polyvinyl pyrolidone (PVP).
5. Natural
and synthetic polymers are in colloidal range. Starch, cellulose are
pharmaceutical adjuncts; synthetic polymers are used as coatings to tablets for
protection against moisture and acid degradation in stomach.
6. Colloidal
dispersions containing radioactive isotopes are used for diagnostic and
therapeutic purposes in nuclear medicine. Technetium 99m sulphur
colloid is used in liver, spleen and bone scanning. Radioactive colloids that
accumulate in tumors, lesions or emboli indicating their location and size may
be used as diagnostics. The radiation emitted is made visible by scanning
devices. Radiocolloids are useful in treatment of cancer because they
accumulate in target organs.
