Posted by lawstud on June 18, 2009, at 23:59:45
In reply to Re: new generic adderall xr, posted by 7Towers on May 3, 2009, at 10:54:51
A lot of people are complaining about Generic Adderall XR, from irritability to feeling sick. Basically Teva which is the only generic maker on the market until October 2009 is making a sh*tty generic with the help of Shire. I've read other places that say generics only need to between 80-120% bio-available.
Although they claim the same bio-availability my research indicates that Shire the brand Adderall XR maker claimed to the FDA in their application mean d-amp and l-amp plasma concentrations blood double what they are not claiming or what TEVA on their website is posting. Hell TEVA just copied the study from Shire and posted it under pharmacokinetics like they ran the study.
The only explanation besides the 80-120% BA is that the beads in the XR in the generic have different rates of release. This is wrong, the drugs dextro-amphetamine-sulfate and dextro-amphetamine-saccharate are the reasons why there is a time release. They are metabolized at different rates because of the polymers used on them. The first drug hits right away while the second is slowly absorbed from 2 to 5 hours peaking at around 7hrs in the body, the polymers and bead creation a trade secret.
Also even if TEVA figured it out, they can't copy the blood plasma levels of brand Adderall XR without violating Shire's patent. Thus the levels of dextroamphetamine and levo-amphetamine in instant and sustained release form in the pills are not going to act the same as brand (and although they claim equal amounts of each drug I seriously doubt they are really doing that).
In addition the beads which the drug are in and on are of different structure between Shire's brand adderall and the TEVA generic. Some beads in the pill are made of sugar with dextro coats, some with polymers to time release, dispersing agents, water barriers to delay absorption etc, while TEVA's beads can be of varying quality and use different polymers.
Bottom line, if brand works and you switch to generic don't make a radical shift but mix and match the pills to get used to them before switching over. Then again either October or November months from April 1st) TEVA is not going to be alone, there will be more generic adderall xr makers then.
poster:lawstud
thread:890876
URL: http://www.dr-bob.org/babble/20090611/msgs/901952.html