ABSTRAL (fentanyl) sublingual tablet is a solid formulation of fentanyl citrate, a potent opioid analgesic intended for oral sublingual administration. ABSTRAL is formulated as a white tablet available in six strengths, distinguishable by the shape of the tablet and by de-bossing on the tablet surface.

Active Ingredient: Fentanyl citrate, USP is N-(1-Phenethyl-4-piperidyl) propionanilide citrate (1:1). Fentanyl is a highly lipophilic compound (octanol-water partition coefficient at pH 7.4 is 816:1) that is freely soluble in organic solvents and sparingly soluble in water (1:40). The molecular weight of the free base is 336.5 (the citrate salt is 528.6). The pKa of the tertiary nitrogens are 7.3 and 8.4. The compound has the following structural formula:

All tablet strengths are expressed as the amount of fentanyl free base, e.g., the 100 mcg strength tablet contains 100 mcg of fentanyl free base.

Inactive Ingredients: Croscarmellose sodium, magnesium stearate, mannitol, and silicified microcrystalline cellulose.