As a potent dosage form, capsules offer many benefits over tablets: their looks are charming
they break down when wet, so are easy to swallow in a glass of water
the drug requires fewer ingredients than the active ingredient
shellfish are inactive and easily digested in the stomach.
they are easy to organize, carry and store
the outer surface can be dark or opaque to protect it from light (eg titanium dioxide).
the shell absorbs the flavors of the ingredients, disposing of tastier inferior medicines.
some disadvantages are:
drugs or hygroscopic ingredients will absorb water from the mouth of the capsule, making it tepid and therefore not suitable for prolonged use.
capsules are readily soluble in water at 37°c and should therefore be stored in a dry environment at low temperature.
a solution of alcohol and oil can dissolve in the capsule, but not in water because it will react with the gelatin shell and destroy it.