butrans - Medication Listings

BUTRANS is a transdermal system providing systemic delivery of buprenorphine, a mu opioid partial agonist analgesic, continuously for 7 days. The chemical name of buprenorphine is 6,14-ethenomorphinan-7-methanol, 17-(cyclopropylmethyl)- α-(1,1-dimethylethyl)-4, 5-epoxy-18, 19-dihydro-3-hydroxy-6-methoxy-α-methyl-, [5α, 7α, (S)]. The structural formula is: The molecular weight of buprenorphine is 467.6; the empirical formula is C 29 H 41 NO 4 . Buprenorphine occurs as a white or almost white powder and is very slightly soluble in water, freely soluble in acetone, soluble in methanol and ether, and slightly soluble in cyclohexane. The pKa is 8.5 and the melting point is about 217°C. System Components and Structure Five different strengths of BUTRANS are available: 5, 7.5, 10, 15, and 20 mcg/hour (Table 6). The proportion of buprenorphine mixed in the adhesive matrix is the same in each of the five strengths. The amount of buprenorphine released from each system per hour is proportional to the active surface area of the system. The skin is the limiting barrier to diffusion from the system into the bloodstream. Table 6: BUTRANS Product Specifications Buprenorphine Delivery Rate (mcg/hour) Active Surface Area (cm 2 ) Total Buprenorphine Content (mg) BUTRANS 5 6.25 5 BUTRANS 7.5 9.375 7.5 BUTRANS 10 12.5 10 BUTRANS 15 18.75 15 BUTRANS 20 25 20 BUTRANS is a rectangular or square, beige-colored system consisting of a protective liner and functional layers. Proceeding from the outer surface toward the surface adhering to the skin, the layers are (1) a beige-colored web backing layer; (2) an adhesive rim without buprenorphine; (3) a separating layer over the buprenorphine-containing adhesive matrix; (4) the buprenorphine-containing adhesive matrix; and (5) a peel-off release liner. Before use, the release liner covering the adhesive layer is removed and discarded. Figure 1: Cross-Section Diagram of BUTRANS (not to scale). The active ingredient in BUTRANS is buprenorphine. The inactive ingredients in each system are: levulinic acid, oleyl oleate, povidone, and polyacrylate cross-linked with aluminum. Chemical Structure Fig 1