Buprenorphine and Naloxone Sublingual Tablets are uncoated, round, white tablet with “↑” on one side and an “N2” or “N8” debossed on the other side. “N2” indicating the 2 mg/0.5 mg strength and the “N8” indicating the 8 mg/2 mg strength. They contain buprenorphine HCl, a mu-opioid receptor partial agonist and a kappa-opioid receptor antagonist, and naloxone HCl dihydrate, an opioid receptor antagonist, at a ratio of 4:1 (ratio of free bases). It is intended for sublingual administration and is available in two dosage strengths, 2 mg buprenorphine with 0.5 mg naloxone and 8 mg buprenorphine with 2 mg naloxone. Each sublingual tablet also contains lactose monohydrate, mannitol, cornstarch, povidone, purified water, citric acid anhydrous, sodium citrate, sodium stearyl fumarate, acesulfame K sweetener, a lemon flavor and a lime flavor.
Chemically, buprenorphine HCl is (2S)-2-[17-Cyclopropylmethyl-4,5α-epoxy-3-hydroxy-6-methoxy-6α,14-ethano-14α-morphinan-7α-yl]-3,3dimethylbutan-2-ol hydrochloride. It has the following chemical structure:
Buprenorphine HCl has the molecular formula C29 H41 NO4 • HCl and the molecular weight is 504.10. It is a white or off-white crystalline powder, sparingly soluble in water, freely soluble in methanol, soluble in alcohol, and practically insoluble in cyclohexane.
Chemically, naloxone HCl dihydrate is 17-Allyl-4, 5 α-epoxy-3, 14-dihydroxymorphinan-6-one hydrochloride dihydrate. It has the following chemical structure:
Naloxone hydrochloride dihydrate has the molecular formula C19H21NO4 • HCl • 2H20 and the molecular weight is 399.87. It is a white to slightly off-white powder and is freely soluble in water, soluble in alcohol, and practically insoluble in toluene and ether.