gelatin shells filled with the ingredients that make up an individual dose.
Dry powders, semi-solids, and liquids that do not dissolve gelatin may be encapsulated.
Capsules account for about 20% of all prescriptions dispensed.
Capsules have several advantages as pharmaceutical dosage forms:
- They may be used to mask the unpleasant tastes, aromas,
or appearance of a drug.
- They allow powders to be dispensed in an uncompressed form, thus allowing
for quicker dissolution and absorption of the drug following oral dosing (as
compared with tablets).
- They offer the pharmacist versitility to prepare any dose desired for a
variety of administration routes (e.g. oral, inhalation, rectal, or to be diluted
for vaginal, rectal, oral or topical use).
- They may be easier than tablets for some people to swallow.
- They can be make to alter the release rate of the drug.
Their disadvantages or limitations include the following:
- They are easily tampered with (although techniques exist
for preventing this).
- They are subject to the effects of relative humidity and
to microbial contamination.
- They may be difficult for some people to swallow.
- More expensive (commercially).