View Full Version : How much Fentanyl is in the adhesive Layer and how much is in the gel

12-13-2009, 01:51 PM
Hi all,
Ive been prescribed the Fentanyl patch for several months now. My doctor recently increased my dosage to 100mcg/hr in exchange for 30mg less of Oxycodone a day. I had no opposition to this because I find the patch delivers the best pain relief out of any of the medications im on.

Here is my question. In the Duragesic gel patches (Brand, Watson, Sandoz, Activis), there is a large ammount of gel, and then a transdermal layer that sticks to your skin. When I wanna extract the gel out, I cut them open a slit WITH the cover still on the back. When I am sick or low on opiates, I take all these "empties" and chew on them, and notice I get a buzz. Some people on this other forum claim that 75% of the fentanyl is in the gel, and the other 25% is in the sticky adhesive layer. What I just did was take all the gel out of my patch, took half of it buccally and the other half I vaporized. Now instead of saving the rest of the patch for when im sick, I still slapped it on (I only cut open a very small ammount), and put a tegaderm dressing on top of it, so it appears that im wearing a patch. Now that im on the 100mcg/hr patch, if this 75/25 theory is correct, one could assume the patch is now a 25mcg/hr patch. Or maybe its not releasing 25mcg/hr, but I can assure you there is still fentanyl in it, and that it is not ALL in the gel, because I have chewed on these empties before when I was sick and it took my sick away. Does anyone have any definitive info on how these gel patches are designed? The ones I have right now are Sandoz, which are made by Alza corp, the same company that makes the brand name Duragesic.

Uncle Wiggly
12-13-2009, 06:51 PM
You seriously need to look at the stickies in this (Fentanyl) forum. I've no idea how much active ingredient is contained in the adhesive. I suspect it may vary due to multiple factors i.e. Temperature, length of time the patch has been worn if at all etc...

12-13-2009, 07:33 PM
I have no idea how much fent is in each part, but this is something I posted on another fent thread:

<icky snip>
This is why the patch works (Duragesic/Mylan). It has a protective liner and four (?) functional layers. First, a backing layer of clear (polyester?) film. Then, the actual fentanyl gel reseviour (alcohol based cellulose). Next, an ethylene -vinyl acetate co-polymer member that controls the rate of the stuff sent to the surface. Finially, a fent-containing silicone adhesive.<snip>I'd be safe to say that a majority of the fent is in the gel, methinks.

12-13-2009, 08:16 PM
i read 25 percent. inspekter dek said sump like on one of the stickies i think. He was talkin bout the gel filled one not the mylan kind,and it was a tek for the extraction with iso.

I was talkin bout the adhesive on a spent duragesic or watson type patch there also haha

12-14-2009, 12:50 PM
Well what I was reffering to was not the adhesive layer on a patch that's been worn for any ammount of time. I'm reffering to a fresh patch, with a tiny hole cut in it to extract all the gel. THEN I am taking the backing off and putting the patch on, and covering it with a tegaderm dressing (the same stuff used in hospitals to keep an iv in) so that an airtight seal is on it. Those things work wonders for any kind of patch, I've taken hour long baths with epson salt with those on, and it still keeps the patch on with no chance of coming off.

I believe many people misunderstood my original question. I'm asking if now that all the gel has been taken out of a 100mcg patch, and that I'm now wearing it with the adhesive layer fresh, is it now a 25mcg patch? Or is it doing anything at all is the real question.

hero 1
12-14-2009, 01:13 PM
I would think that the membrain controls the rate of the dose not the amount in the patch.If I am correct the sizes are diffrent so the area of the patch would control the rate of the dose.No doubt that there is some dope in the sticky layer how much would be any ones guess and I geuss bout an hours worth.Enough to get the thing rolling

12-14-2009, 01:17 PM
I give up.

Uncle Wiggly
12-14-2009, 01:20 PM
It's a pretty difficult question to answer. You may find out something on the Sandoz website. When swim was on a Fent smoking spree he would chew the empties when the gels was gone.

Swim used to get 15-100Mcg + 15 25 or 50Mcg per month. The patches would last 3 to 10 days depending on swims mood. Swim would chew an empty 100 + a 50. This would keep the dogs at bay for 4 - 6 hours.

You probably already know this but when your chewing your empties you need to hold your spit in for at least 20 minutes for them to work. Swim has been known to hold it in for 45 minutes, however drooling can be an issue. :rolleyes:

EDIT: Swim doesn't know you but he sure does owe you. He was just looking in his "Special" drawer to find an empty patch wrapper to get Sandoz' URL and just now found three 100Mcg that he tucked away about a year ago. Thank you. Thank you. Thank you. Swim can't believe he forgot about those.
YeeHaw - it's going to be a fun day/night! :D :D :D

12-14-2009, 01:21 PM
It's a pretty difficult question to answer. You may find out something on the Sandoz website.

Thats a great resource, good idea.

12-14-2009, 01:34 PM
Someone always soaks his empties in ethanol(after cutting them up), then evaps for more pleasures. I only get the Sandoz when I get mine filled, from my exp they are the best, for any use, intended or illicit.

Personally I don't think there nowhere near 25% of the fentanyl in the adhesive or sticky layer... ESPECIALLY if the patch is still new without even having the lil film covering the sticky peeled off.. Now if the patch had been worn for a while, I'd say there would be some fent in there(still not no 25%), but maybe like 1-4hours doses(25-100mcg depending on patch strength).
But for a brand new unworn patch that has had the gellies squeezed out, I don't think there is much at all left. I think there is more fent stuck to the path wall and the membrane which controls the release of the fent than anywhere else...

Like when someone extracts any remaining fent from the empties(basic ethanol extraction) it takes about 5 empties to get a few hits(foiled). Someone is on the 50mcg/hr(10x) and 12mcg/hr patches(5x). but yeah I just don't see how anywhere near 25% of the fent could be in the adhesive sticky part... Even after wearing and having fent moving through it.


12-14-2009, 01:41 PM
Ah the Insane Ike! Nice to see you post here, dood.

12-14-2009, 05:54 PM
its 25 percent i read it on here...he said if u get 4 100s you should get 25 mic back which means 25 percent in each patch

12-15-2009, 02:41 PM
its 25 percent i read it on here...he said if u get 4 100s you should get 25 mic back which means 25 percent in each patch

yep, its in the first sticky right above this topic

12-15-2009, 02:45 PM
im with the ike man

Uncle Wiggly
12-15-2009, 03:51 PM
Hey DD, Nice to see you around.

25% / 4 = 6.25% :rolleyes: Duh

If it were 25% in each patch four would = 100% (Mcg.)

12-16-2009, 03:36 PM
I don't know how much is in the backing, but my pharmacist told me that about 18% of the gel remains in the patches after 3 days. Her point was the used patch needed to be disposed of carefully as enough fent was in it to kill a child or pet.

If I covered my gel patch with a Tegaderm patch, I was able to get 3.5 to 4 days of wear out of it. I was amazed at how much gel remained in the patch after 3 days. If worn a 4th day, there was almost no visible gel left in my patches.

I don't know if the thread is still here, but Uncle Wiggly posted a picture of the "Fent Pipe" he made and it was an awesome invention. There was a lot of good info in the Fent threads.