Fentanyl suspension-based silicone adhesive formulations and devices for transdermal delivery of fentanyl

1. A method for making a monolithic suspension-blend transdermal patch comprising: (a) contacting an inner layer of a backing layer having inner and outer surfaces and being substantially impervious to fentanyl with first surface of a first adhesive layer, the adhesive layer comprising a uniform suspension of a 72 to 168 hour period therapeutically-effective amount of fentanyl particles suspended in a silicone adhesive, the fentanyl particles consisting essentially of non-recrystallized fentanyl, the silicone adhesive comprising heptane solvent fully-solvated silicone adhesive from which the heptane solvent is substantially removed, the heptane solvated adhesive being incapable of dissolving greater than 1% w/w of said fentanyl particles; and (b) contacting a second surface of the adhesive layer with a removable release liner; wherein the fentanyl load of the suspension-based patch ranges from about 1 to about 15% w/w (dry weight) based upon the weight of the fentanyl silicone adhesive suspension; whereby when the suspension-blend patch is administered to a subject in need thereof, the adhesive layer delivers from about 5 μg/hr to about 250 μg/hr of the fentanyl to the subject for the period.