Sublabial administration

Sublabial, literally 'under the lip', from Latin, refers to the pharmacological route of administration by which the active substance is placed between the lip and the gingiva. The frenula may be irritated when in contact with corrosive materials but can be avoided with this route.

It is usually used for drugs such as Glyceryl trinitrate, for example, in angina pectoris.

Upper lip administration

Some drugs are inactive in the digestive tract, but this can be avoided if held between the upper lip and gum. This prevents the substances from getting swallowed with salivation, as would normally occur between the lower lip and gum, permitting slow release of the drug to prolong the duration of action.