SPL Set ID: 0ff70df0-2cda-d96c-42a8-3bf180310498

Fentanyl transdermal system contains fentanyl, an opioid agonist, for transdermal administration. The amount of fentanyl released from each system per hour is proportional to the surface area (25 mcg/hour per 10.5 cm 2 ). The composition per unit area of all transdermal system sizes is identical. Strength* (mcg/hour) Size (cm 2 ) Fentanyl Content (mg) Color of Printing on Back of Patch 12** 5.35 1.38 Orange 25 10.7 2.76 Pink 37.5 50 16.05 21.4 4.14 5.52 Green Green 62.5 75 26.75 32.1 6.90 8.28 Green Blue 87.5 100 37.45 42.8 9.66 11.04 Green Gray * Nominal delivery rate is 12.5 mcg/hour ** Nominal delivery rate per hour The molecular weight of fentanyl base is 336.5 g/mol, and the empirical formula is C 22 H 28 N 2 O. The n-octanol: water partition coefficient is 860:1. The pKa is 8.4. The chemical name is N-phenyl-N-(1-(2-phenylethyl)-4-piperidinyl) propanamide. The structural formula is: Fentanyl transdermal system is a rectangular unit comprising a release liner and two functional layers. Proceeding from the outer surface toward the surface adhering to skin, these layers are: 1) a backing layer of polyethylene/aluminum/polyester film; 2) a drug-in-adhesive layer. Before use, a release liner covering the drug-in-adhesive layer is removed and discarded. Structure Structure