Reta shelf life after mixing?

Calorie_Cake

Well-known member
Hey all,

I realize this is a bit of a grey area, mixing personal experience with some science. But I'm really interested in experiences, especially from those on lower doses of Reta.

I'm about to start a Reta trial and think I'll respond well to a lower dose, based on my experience with sema. If that's right, a 10mg vial could last me over two months after mixing. I'll keep it in the fridge, thinking that'll help, and probably in the vial itself, not a pen... which I like more. But still:

How long do you think a mixed vial of reta can last if you keep it sterile and cold?
 
Way longer than people are saying! A couple months, easy. 10 weeks is no prob if you mix carefully and dose right. Rx GLP-1s last for years, man. Two and a half months? You're golden.
 
I'd agree with that. But the number of pokes into the stopper becomes a thing. Like, daily dosing would be too many. I'd cap it at, say, 20 pokes, definitely under 10 would be best.
 
I'm not familiar with reta, but insulin pens have documented backwash into the cartridge. (They found human white blood cells.) Insulin's got tons of preservatives, like phenol and benzyl alcohol.

Just do a search, I looked this up once.
 
I'm surprised testing labs haven't looked into this. If I had a lab, I'd mix some vials and keep them in the fridge, checking one at 3 months, 6 months, 9 months, and a year, just to see how it degrades. Bacteria's a concern, but knowing pep stability under normal conditions would be interesting and not safe to assume reta's as stable as tirz.
 
I used to work 2 weeks on/off and was gone for over 2 weeks, so vials lasted me longer. I've used them for months with no problems, but I'm super careful about cleanliness. A vial spike can minimize punctures if a vial's going to last a while.
 
True, Big_Fit, but the needle's in your body, so there's a fluid connection. Backwash happens. A third of insulin pens tested had it, and they have way more preservatives and a longer official date.
 
Does anyone have instructions for vial spikes that protect vials longer than 4 weeks? It doesn't make sense that they're better, stabbing a bigger hole in the stopper. (They also need the right stopper or they can damage the seal.)

Not all vial spikes are closed systems, and even those only work for a week, then you toss the vial. They might be very sanitary for a short time if they're closed systems, but maybe they weaken the seal? How much this matters for sub-q shots is a question. I haven't heard pharmacies recommend this.
 
Just finished a vial after 3 months. Still worked fine, and I kept it cold. Always wiped it with alcohol.
 
I think some pen usage habits increase backwash risk. Reusing needles is common, but the recommendation is under 6 times (or you get nodules and infections). Also, leaving the needle on increases risk.

Hospitals should have lower rates of backwash. But it's still surprising to me that it's that high.

Vials also have a small contamination risk per puncture. I don't have the reference, but a search should find stuff. Many studies are from outside the US.
 
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