JOHN, i haven't looked at this for awhile but generic mfgs don't have to test their drugs on pd'ers, i believe they test only on non-pd'ers' for blood levels. i can understand the reasoning there. and up until recently there has been no testing required for a generic ER (extended release) version to have a similar drug release pattern, i.e., in a healthy patient, what is the half-life and they don't have to prove that it's as long as the brand name. you can assume that the generic mfg would want to be close to the brand name's ER characteristics but i doubt there are that many patients taking brand name sinemet to notice a difference because insurance companies won't readily pay the higher cost. and to totally upset the apple cart, the original mfg of sinemet is squibb who prior to 2012 paid MERCK to make sinemet and MERCK contracts with mylan to make the drug, check the SINEMET insert, there's a picture of the tiny picture on every SINEMET label saying MFG'ED BY MYLAN. So in this case, i'm not sure what numbers the FDA uses to determine if a new generic sinemet's l-dopa peak concentration is ok, i assume MERCK, since i assume that the generic testing involves testing the current brand name, not just using +30 year old numbers from squibb. i'm not criticizing the MYLAN brand, i like it. i liked teva better but they sold off their generic rights along with their rights to the ACTAVIS brand to MAYNE when they bought ALLERGAN which ownd the indian mfg ACTAVIS. The end result is no more TEVA c/l and MAYNE is now selling the C/L made by ACTAVIS and possibly SUN is selling the ACTAVIS manufactured product?

i've noticed differences with some generics, primarily i just feel sick when taking it and/or less relief, i blame feeling sick on dyes, fillers and possible contaminants plus the extra stuff they add to the ER variations to slowly break down and release little chunks of tablet which extends it's lifetime. i assume the reason C/L ER releases C/L for a longer time period than the IR C/L is for that reason, the longer it is protected from enzymes in the stomach breaking down the l-dopa, the greater chance of more l-dopa getting to the small intestine where it is absorbed. that's why you want to slow your stomach emptying a little when taking C/R, if you speed up emptying by taking CR on an empty stomach more of it will leave the stomach still in the pill form which will pass right by the area of the small intestine where it is absorbed. i have to admit i've never found information on the internet describing exactly how CR C/L works to slow release but my guess sounds pretty good?

this is a complicated subject and i'm no expert. all i can say is try to have a 30 day backup supply, more if possible, of your C/L regardless of whether you think one generic is better than another. disruptions in supply chains are going to become more common with global warming and more raw ingredients bought from other countries, especially china and india and more mfg'i
ng occurring in lesser developed countries. there's just a greater chance of a plant being damaged like what happened to mylan in puerto rico, where the mfg and wholesalers didn't have enough inventory to keep supplying the drug or god forbid, trump puts a tariff on some ingredients used in manufacturing ER (cr) C/L, maybe some rare wax, or a bad batch of drug is manufactured for a myriad of reasons. and manufacturers can make a bad batch of drugs, doesn't happen often so good to have some pills from an older batch to compare against. this ain't no trivial matter, a small difference in strength or with the CR/ER versions poor quality or just more of the addons to make the pill dissolve slowly MIGHT make that generic intolerable imho. i kind of feel like i might be unusually sensitive to differences and my neuro doesn't believe there are major differences so i may just be creating a false alarm. fwiw, here's an interesting marketing paper from merck, i think 2011 date, where they make the argument that name brand is better!! is it just patient perception? i forgot to point out that even though MYLAN mfg's SINEMET for MERCK, the mylan and MERCK tablets aren't absolutely identical,the mylan is scored, the brand name isn't. and i don't know if the formulas are the same.
Parkinson drug sinemet-LIFE CYCLE STRATEGIC PLAN

"A problem in manufacturing change from Merck to Mylan in 2010 lead to worldwide shortage.  Despite the differences of Mylan Sinemet from Merck Sinemet, it is still more effective than generic formulations"


this is in the presentation:

Non-medicinal ingredients • Crospovidone, hydroxypropylcellulose, magnesium stearate, microcrystalline cellulose, pregelatinized starch Storage and stability • Store your tablets at room temperature (15°C–30°C). Store in tightly closed container, protected from light and moisture.

this presentation is very interesting if you want more info on CL in general, it's history and how it works. best quick read i've seen.