2. Weighing Method: It is a important operation
that takes part in dispensing of the dosage
forms. The quality of the dispensed drug
depends on the accuracy in the weighing
process.So,until we know about the proper
techniques of weighing either by dispensing
balance or analytical balance,it is not
possible to supply quality product to the
patients.
3. • A cleaned balance must be put in a well
lighted room which is free from dust,
corrosive vapors high humidity and air
vibrations.
• Adjust the level of the balance.
• Cut two equal sized wax papers and put
them on each of the pan so as to cancel the
weight of paper on which powder is kept.
Papers will also prevent the direct contact of
powders with pan and hence preventing the
corrosion of pans and adhering of powders
to the pans.
4. Clean the balance pan and spatula with the
duster.
Return the weights from the pan to their
proper places with the help or forcep.
The pointer shows a zero reading after
releasing the pan arrest when a correct
amount of powder is taken on the pan.
Once again the pointer of balance is
checked. it should be absolutely on the zero
point in releasing condition. then put the
pans on arrest condition.
5. Balance is not leveled.
Rest point of balance is defective.
Two pans are having different weight.
Position of left and right pans is
interchanged.
Wax papers on both the pans are not having
similar weight.
Weighing is performed directly on the pan.
Weights are handled with hands.
Fractional weights are not calibrated.
6. By using digital single pan balance or an
analytical balance for weighing a very small
quantities of potent drug.
By using prefabricated dosage form,such as
tablet triturates, dispensing tablets or
hypodermic tablets of the same drug for the
convenience of patient and pharmacist.
The minimum weighable quantity in an
electronic balance is 1 mg. This may vary
from place to place. For example this is for
the electronic balance that is used in the
groceries shop.
7. It is the method of mixing of powders.
The method is used when potent substance are
to mixed with a large amount of diluent.
The potent drug is placed upon an approximately
eual volume of the diluent in a mortar is added
and trituration is repeated.
A second portion of diluent equal in volume to
the powder mixture in the mortar is added and
trituration is repeated.
The process is continued ,adding diluent equal in
volume to the mixture in the mortar at each
step,until all the diluent is incorporated.
