Different companies, hell, even different batches, of drugs can differ significantly. For a generic to be approved in the US, it must prove to give the same dose, +/- 25% of the "original" brand name.
On top of that, individual tablets can vary by several, up to 10%, in drug content.
On top of that, many. many drugs have pharmacokinetics that are affected by the specific formulation (recipe of inactive ingredients and method of manufacture) and generic drugs often have formulations that differ from the original, brand name drug.
I base the above on my knowledge of the US pharma industry and regulations from a decade in the field.
So... yes, your new brand may be stronger or have faster/better/more complete release of drug than the previous brand. This is to be expected given variations in formulations, etc. .
But I really hope you don't use benzos daily, no matter your need. The WDs I experienced were far worse than opiate WDs I got from oxy or U-47700, and it took 6 months for me to break a habit I inadvertently developed over a month of daily benzo use. Fuck those drugs. They can be a life saver- I try to keep some on hand- but they are profoundly dangerous used regularly. The WDs can actually KILL you.
TL/DR: I'm sure you as you recall better, tablet content uniformity limits for genetics are: nominal assay value of +/- 15%, for 10 random tablets with SD =< 2, possibly could be SD =<1, not simply 25% of nominal label value, a limit that high could endanger patients. Standard deviation is employed to provide precision data for that batch, it ensures that the tablets don't vary to much (e.g., 112%, 86%, and so on, in the ten tablet sample.
20 tablet combined assays limits are 90 - 110%, typically. That means 20 random tablets from a batch tested in one solution, for most compounds. Some are tighter, I believe Warfarin is tighter, 95 - 105.
Explanation: going a bit off topic, but i need to correct what I continue to read as incorrect info about the genetic industry.
A few compounds, nitroglycerin, l-thyroxine or Digoxin - likely have tighter limits. Most compounds adhere to the above, several require tighter limits.
Definitive source for all U.S. approved drugs, marketed in time to be included in the latest release, have analytical limits and much other info, in the United States Pharmacope. I suggest anyone having issues with a compund look up the compound. Each generic is absolutely going met those criteria, and not create a noticeable difference esp., if you reach steady plasma state, if not you may notice.
Many brand drug manufactures produce genetic equivalents of their own compounds and so are likely identical formulations with different imprints. Then talk to your pharmacist (or "chemist" for the limeys) and NOT your physician, then take your findings to your next appointment, physicians generally know jack. Pharmacists are much better educated.
Consider the vast majority of consumers notice no difference when switching manufacturers, some even find them more effective! But those stories are not as well published.
Post-marketing genuine clinical trials with "real world conditions" that run for say, three years and include a statistically significant # of compliant consumers, seems to be the best data we can gather to date. I believe if a compound fails the original trial limits it should be pulled from the market, while excepting those that had positive effects, but no new patients.
Imagine if Purdue had done that with OCs? They did but refused to publish the results, several times over. Instead the FDA & independent groups eventually did it on their behalf. Boom, the 'oxy OC was of the bottle'. It took about a decade to figure it was highly addictive (took me about three days). Post clinical trials aren't that expensive, some other entity pays for everything but ensuring compliance and providing blinded data, the innovator pays for independent statistical analysis.
This info comes from my experience as a formulation scientist and analytical chemistry method development chemist in the genetic industry. And a recent read of the pharmacopea.
I could be wrong, but only if FDA / ICH widened the limits on standard testing of tablets and capsules. I can't speak about IV/IM, rectal, sublingual, etc... formulations. Ever wonder how genetic equivalents are develoved, gain or are denied approval, PM with questions.
