starch, talc, lactose to prevent dampness of the powder and dispensing the components of the eutectic
mixture separately.
6. Cachets
Cachet as a unit dosage form was very popular sometime back. Presently cachets are seldom
used and have been replaced by capsules. Cachets, like capsules, can be easily filled and sealed at the
dispensing counter.
This dosage form holds larger quantity of the medication as compared to capsules. Since the
cachets are made of flour and water they are easily damaged in handling. Further this dosage form
offers little protection against light and moisture.
Due to its size and shape a cachet is difficult to swallow. The process of filling is similar to that of
capsules. The drug is placed in one of the two halves of the cachet, the upper half is then placed over it
and pressed with the help of a suitable device.
The flange of the upper plate is moistened carefully taking care not to wet it, with the help of a
dampener. The sealing takes place due to the moisture between the flanges of the upper and the lower
half and the pressure over the flanges. About 15 minutes are allowed for drying of the seal.
After this time the middle portion of the cachet is slightly pressed to ensure complete sealing. In
absence of a machine a pharmacist can improvise and use two bottles the mouths of which are broad
enough so that flanges of the plates - upper and lower, when kept over the mouths of the bottles, just
rest over them. The drug is transferred to one of the plates resting over the mouth of the bottle kept
vertically on the working bench. The flange of the empty half resting over the mouth of another bottle is
moistened with the help of a damp camel hair brush.
The empty half of the cachet is then placed over the other half in which the medication is kept
so that the flanges of the two halves are perfectly superimposed. The second bottle is then inverted and
brought over the superimposed cachet and carefully put over the flange and pressed in position without
disturbing the resting place of the cachet.
This provides a good seal. Cachets can be dry-sealed also. These cachets however are of a
different shape where the cap is pressed over the body of the cachet. A protruded stud is also provided
to hold the upper and lower halves together.
Like capsules, cachets are also expected to remain untouched by hand and one should use
gloves while handling them. Since there are inherent losses of the drug in this operation also like that of
powders and capsules, the quantities of each ingredient should be weighed for an extra powder over
the number to be dispensed. The cachets are dispensed in wide-mouthed bottles of glass or plastic with
a perfectly fitting cap. The patient should be instructed to keep the bottle securely closed.
Cachets are of two types:
(a) Wet seal Cachets and
(b) Dry seal Cachets
(a) Wet seal Cachets:
They are made up of two similar covex halves having flat edges The weighed amount of powder
is placed in one half; the edges of the other are moistened with water and placed exactly over the first