Some of the insufflations contain volatile liquid ingredients which may require uniform
distribution in the powder. If these liquid ingredients are present in large quantity, the liquid portion
may have to be evaporated. Generally evaporation is brought about slowly in a china dish which is
heated on a water bath. The resultant product is re-powdered and sifted through a sieve of a suitable
size.
However, active volatile liquids present in small portions should not be removed by evaporation
but only incorporated by trituration in the powder.
The pharmaceutical industry packages the insufflations in pressurized form i.e., aerosols.
Aerosols contain the medication in a stout container with a suitable valve, the delivery of the powder
being accomplished by a liquefied or compressed gas propellant of very low boiling point. On pressing
the actuator of the valve the propellant delivers the medication in a stream.
2. Bulk powders for internal use
Bulk powders contain many doses in a wide-mouth container that is suitable to remove the
powder by a teaspoon. The non-potent substances are used in bulk powder form such as antacid,
laxative, purgative, etc.
Rhubarb powder
Light magnesium carbonate
Heavy magnesium carbonate
Ginger powder
Make a powder.
3. Simple and compound powders for internal use
These are unit dose powders normally packed in properly folded papers and dispensed in
envelopes, metal foil, small heat-sealed plastic bags or other containers.
Usually for the preparation of simple powders, the ingredients are weighed correctly and
blended by geometrical mixing in ascending order of weights. The mixture is then either divided into
blocks of equal size, numbers of blocks representing the number of powders to be dispensed or each
dose is weighed separately and placed on a powder paper. The paper is then folded according to the
pharmaceutical art and placed in either an envelope or a powder box.
4. Effervescent granules
This class of preparations can be supplied either by compounding the ingredients as granules or
dispensed in the form of salts. The ingredients whether in granular form or present as salts, react in
presence of water evolving carbon dioxide gas.
For evolution of the gas two constituents are essential, a soluble carbonate such as sodium
bicarbonate and an organic acid such as citric or tartaric acid. The preparation can be supplied either as
a bulk powder or distributed in individual powders.
There are three alternative methods of dispensing depending upon the nature of prescription.
(i) If the effervescent salts are prescribed to be the dispensed in bulk form, no granulation is
necessary. The ingredients are mixed uniformly and directions stated on the label to add the prescribed
quantity to water, before use.