Drugs Similar to FENTANYL

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) 12** 5.35 1.38 25 10.7 2.76 37.5 50 16.05 21.4 4.14 5.52 62.5 75 26.75 32.1 6.90 8.28 87.5 100 37.45 42.8 9.66 11.04 * Nominal delivery rate per hour ** Nominal delivery rate is 12.5 mcg/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 transparent 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 terephalate film; 2) a drug-in-adhesive layer. Before use, a release liner covering the drug-in-adhesive layer is removed and discarded. image description image description

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

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 Nominal delivery rate per hour (mcg/hour) Size (cm 2 ) Fentanyl Content (mg) 12 Nominal delivery rate is 12.5 mcg/hour 5.35 1.38 25 10.7 2.76 37.5 16.05 4.14 50 21.4 5.52 62.5 26.75 6.90 75 32.1 8.28 87.5 37.45 9.66 100 42.8 11.04 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 transparent 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 terephalate film; 2) a drug-in-adhesive layer. Before use, a release liner covering the drug-in-adhesive layer is removed and discarded. Structure Patch

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) 12** 5.35 1.38 25 10.7 2.76 37.5 50 16.05 21.4 4.14 5.52 62.5 75 26.75 32.1 6.90 8.28 87.5 100 37.45 42.8 9.66 11.04 * Nominal delivery rate per hour ** Nominal delivery rate is 12.5 mcg/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 transparent 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 terephalate film; 2) a drug-in-adhesive layer. Before use, a release liner covering the drug-in-adhesive layer is removed and discarded.

The 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 6.25 cm 2 ). The composition per unit area of all transdermal system sizes is identical. Strength (mcg/hour) Size (cm 2 ) Fentanyl Content (mg) 12 Nominal delivery rate is 12.5 mcg/hour 3.13 1.28 25 Nominal delivery rate per hour 6.25 2.55 37.5 9.38 3.83 50 12.5 5.10 62.5 15.63 6.38 75 18.75 7.65 87.5 21.88 8.93 100 25 10.20 The molecular weight of fentanyl base is 336.5, and the molecular 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 translucent system with rounded corners. “Fentanyl”, dosage strength and diagonal lines are printed in blue ink on each system. Each system is comprised of a polyester release liner and two functional layers. Proceeding from the outer surface toward the surface adhering to skin, these functional layers are: 1) a backing layer of translucent polyolefin film with blue print; 2) a drug-in-adhesive layer containing fentanyl as the active ingredient and dimethicone NF and silicone adhesive as inactive ingredients. Before use, a polyester release liner covering the drug-in-adhesive layer is removed and discarded. Fentanyl transdermal systems are packaged with additional pieces of protective film above and below the system within each pouch. These are discarded at the time of use. Fentanyl Structural Formula Parts of the Fentanyl Transdermal System

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) 12** 5.35 1.38 25 10.7 2.76 37.5 50 16.05 21.4 4.14 5.52 62.5 75 26.75 32.1 6.90 8.28 87.5 100 37.45 42.8 9.66 11.04 * Nominal delivery rate per hour ** Nominal delivery rate is 12.5 mcg/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 transparent 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 terephalate film; 2) a drug-in-adhesive layer. Before use, a release liner covering the drug-in-adhesive layer is removed and discarded. image description image description

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

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 Nominal delivery rate per hour (mcg/hour) Size (cm 2 ) Fentanyl Content (mg) 12 Nominal delivery rate is 12.5 mcg/hour 5.35 1.38 25 10.7 2.76 37.5 16.05 4.14 50 21.4 5.52 62.5 26.75 6.90 75 32.1 8.28 87.5 37.45 9.66 100 42.8 11.04 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 transparent 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 terephalate film; 2) a drug-in-adhesive layer. Before use, a release liner covering the drug-in-adhesive layer is removed and discarded. Structure Patch

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) 12** 5.35 1.38 25 10.7 2.76 37.5 50 16.05 21.4 4.14 5.52 62.5 75 26.75 32.1 6.90 8.28 87.5 100 37.45 42.8 9.66 11.04 * Nominal delivery rate per hour ** Nominal delivery rate is 12.5 mcg/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 transparent 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 terephalate film; 2) a drug-in-adhesive layer. Before use, a release liner covering the drug-in-adhesive layer is removed and discarded.

The 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 6.25 cm 2 ). The composition per unit area of all transdermal system sizes is identical. Strength (mcg/hour) Size (cm 2 ) Fentanyl Content (mg) 12 Nominal delivery rate is 12.5 mcg/hour 3.13 1.28 25 Nominal delivery rate per hour 6.25 2.55 37.5 9.38 3.83 50 12.5 5.10 62.5 15.63 6.38 75 18.75 7.65 87.5 21.88 8.93 100 25 10.20 The molecular weight of fentanyl base is 336.5, and the molecular 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 translucent system with rounded corners. “Fentanyl”, dosage strength and diagonal lines are printed in blue ink on each system. Each system is comprised of a polyester release liner and two functional layers. Proceeding from the outer surface toward the surface adhering to skin, these functional layers are: 1) a backing layer of translucent polyolefin film with blue print; 2) a drug-in-adhesive layer containing fentanyl as the active ingredient and dimethicone NF and silicone adhesive as inactive ingredients. Before use, a polyester release liner covering the drug-in-adhesive layer is removed and discarded. Fentanyl transdermal systems are packaged with additional pieces of protective film above and below the system within each pouch. These are discarded at the time of use. Fentanyl Structural Formula Parts of the Fentanyl Transdermal System

The 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 9.44 cm 2 ). The composition per unit area of all transdermal system sizes is identical. * Nominal delivery rate is 12.5 mcg/hour per hour ** Nominal delivery rate per hour Strength (mcg/hour) Size (cm²) Fentanyl Content (mg) 12* 4.72 1.33 25** 9.44 2.66 50** 18.88 5.32 75** 28.32 7.99 100** 37.76 10.65 The molecular weight of fentanyl base is 336.5, and the molecular 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 translucent system with rounded corners. The product name, “FENTANYL” and dosage strength are printed in green on each system. Each system is comprised of a clear fluoropolymer coated polyethylene terephthalate (PET) release liner and two functional layers. Proceeding from the outer surface toward the surface adhering to skin, these functional layers are: 1) a translucent backing layer of ethylene vinyl acetate/polyethylene terephthalate (EVA/PET) film with green print; 2) a drug-in-adhesive layer containing fentanyl, acrylate copolymer adhesive, and methyl laurate. Before use, a clear fluoropolymer coated PET release liner covering the drug-in-adhesive layer is removed and discarded. Structural Formula Parts of the Fentanyl Transdermal System Patch

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

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 Nominal delivery rate per hour (mcg/hour) Size (cm 2 ) Fentanyl Content (mg) 12 Nominal delivery rate is 12.5 mcg/hour 5.35 1.38 25 10.7 2.76 37.5 16.05 4.14 50 21.4 5.52 62.5 26.75 6.90 75 32.1 8.28 87.5 37.45 9.66 100 42.8 11.04 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 transparent 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 terephalate film; 2) a drug-in-adhesive layer. Before use, a release liner covering the drug-in-adhesive layer is removed and discarded. Structure Patch

The 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 6.25 cm 2 ). The composition per unit area of all transdermal system sizes is identical. Strength (mcg/hour) Size (cm 2 ) Fentanyl Content (mg) 12 Nominal delivery rate is 12.5 mcg/hour 3.13 1.28 25 Nominal delivery rate per hour 6.25 2.55 37.5 9.38 3.83 50 12.5 5.10 62.5 15.63 6.38 75 18.75 7.65 87.5 21.88 8.93 100 25 10.20 The molecular weight of fentanyl base is 336.5, and the molecular 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 translucent system with rounded corners. “Fentanyl”, dosage strength and diagonal lines are printed in blue ink on each system. Each system is comprised of a polyester release liner and two functional layers. Proceeding from the outer surface toward the surface adhering to skin, these functional layers are: 1) a backing layer of translucent polyolefin film with blue print; 2) a drug-in-adhesive layer containing fentanyl as the active ingredient and dimethicone NF and silicone adhesive as inactive ingredients. Before use, a polyester release liner covering the drug-in-adhesive layer is removed and discarded. Fentanyl transdermal systems are packaged with additional pieces of protective film above and below the system within each pouch. These are discarded at the time of use. Fentanyl Structural Formula Parts of the Fentanyl Transdermal System

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) 12** 5.35 1.38 25 10.7 2.76 37.5 50 16.05 21.4 4.14 5.52 62.5 75 26.75 32.1 6.90 8.28 87.5 100 37.45 42.8 9.66 11.04 * Nominal delivery rate per hour ** Nominal delivery rate is 12.5 mcg/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 transparent 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 terephalate film; 2) a drug-in-adhesive layer. Before use, a release liner covering the drug-in-adhesive layer is removed and discarded. image description image description

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) 12** 5.35 1.38 25 10.7 2.76 37.5 50 16.05 21.4 4.14 5.52 62.5 75 26.75 32.1 6.90 8.28 87.5 100 37.45 42.8 9.66 11.04 * Nominal delivery rate per hour ** Nominal delivery rate is 12.5 mcg/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 transparent 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 terephalate film; 2) a drug-in-adhesive layer. Before use, a release liner covering the drug-in-adhesive layer is removed and discarded.

The 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 9.44 cm 2 ). The composition per unit area of all transdermal system sizes is identical. * Nominal delivery rate is 12.5 mcg/hour per hour ** Nominal delivery rate per hour Strength (mcg/hour) Size (cm²) Fentanyl Content (mg) 12* 4.72 1.33 25** 9.44 2.66 50** 18.88 5.32 75** 28.32 7.99 100** 37.76 10.65 The molecular weight of fentanyl base is 336.5, and the molecular 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 translucent system with rounded corners. The product name, “FENTANYL” and dosage strength are printed in green on each system. Each system is comprised of a clear fluoropolymer coated polyethylene terephthalate (PET) release liner and two functional layers. Proceeding from the outer surface toward the surface adhering to skin, these functional layers are: 1) a translucent backing layer of ethylene vinyl acetate/polyethylene terephthalate (EVA/PET) film with green print; 2) a drug-in-adhesive layer containing fentanyl, acrylate copolymer adhesive, and methyl laurate. Before use, a clear fluoropolymer coated PET release liner covering the drug-in-adhesive layer is removed and discarded. Structural Formula Parts of the Fentanyl Transdermal System Patch

Fentanyl transdermal system contains fentanyl, an opioid agonist, available as a patch for transdermal administration. The amount of fentanyl released from each system per hour is proportional to the surface area (25 mcg/hr per 7.8 cm 2 ). The composition per unit area of all system sizes is identical. Strength (mcg/hr) Size (cm 2 ) Fentanyl Content (mg) Color of Printing on Back of Patch 12 Nominal delivery rate is 12.5 mcg/hr 3.9 1.375 Green 25 Nominal delivery rate per hour 7.8 2.75 Green 37.5 11.7 4.125 Green 50 15.6 5.50 Green 62.5 19.6 6.875 Green 75 23.4 8.25 Green 100 31.3 11.0 Green 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 systems are a rectangular, opaque patch with rounded corners: 12 mcg/hr: Fentanyl Transdermal System 12 mcg/hr printed in green 25 mcg/hr: Fentanyl Transdermal System 25 mcg/hr printed in green 37.5 mcg/hr: Fentanyl Transdermal System 37.5 mcg/hr printed in green 50 mcg/hr: Fentanyl Transdermal System 50 mcg/hr printed in green 62.5 mcg/hr: Fentanyl Transdermal System 62.5 mcg/hr printed in green 75 mcg/hr: Fentanyl Transdermal System 75 mcg/hr printed in green 100 mcg/hr: Fentanyl Transdermal System 100 mcg/hr printed in green The 12 mcg/hour system has a green border and the 25, 37.5, 50, 62.5, 75 and 100 mcg/hour systems have green stripes that increase in number with each sequential increasing dosage strength. Fentanyl transdermal system is a rectangular opaque unit comprising a protective liner and four functional layers. Proceeding from the outer surface toward the surface adhering to skin, these layers are: 1) a backing layer of PET foil; 2) a drug containing layer of fentanyl and dipropylene glycol with hydroxypropyl cellulose; 3) an ethylene vinyl-acetate copolymer membrane that controls the rate of fentanyl delivery to the skin surface; and 4) a silicone adhesive. Before use, a protective liner covering the adhesive layer is removed and discarded. Chemical Structure Fentanyl Transdermal System Rectangular Unit