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Brian, where does your source get the information that the center of a CR is any different than the rest of the tablet? This would imply the tablet is made in layers (which it is not) and each layer may be different (which does not exist). Sinement CR comes in two sizes 50/200 which has a score mark and 25/100 which does not have a score mark. The 50/200 can be broken and in published reports actually yields more benefit when two halfs are taken rather than a whole tablet. The PDR says that the bioavailability of levodopa in elderly patients (ages 55 to 66) is 70-75%. The bioavailability in young patients is 44%. When questioned about the difference, one neurologist says that the bioavailability is so variable that if the drug works, use it, if it doesn't try another approach. Another neurologist says that young people have a more active digestive system causing the tablet to pass through too fast. I know the first explanation is correct, CR is highly variable. The second explanation makes sense to me also. When CR was first released it was given to almost all patients as the solution to all problems. I remember visiting my neurologist during those days and he had three stacks of patient folders on his desk waiting for a return call. If you read the literature from the manufacture, 50/200 CR taken every six hours is expected to yield a smoother blood plasma level then two regular 25/100 taken at 3 hour intervals. What is not shown is the potential OFF period that may be experienced while the first CR dies and the second CR becomes productive. If you think of it, the last hour of the first CR is nosediving in benefit yet it will take as much as two hours to reach peak blood plasma level with the second CR. This leaves a low that may be an OFF between tablets. One way to solve this is to start the second CR 5 hours after the first. A little cost analysis. Sinemet CR 50/200 is usually priced at twice that of a regular Sinemet 25/100. Lets assume regular Sinemet 25/100 costs 50 cents than a Sinemet CR 50/200 costs $1.00. If we need to take a CR every 5 hours the cost of a CR becomes $1.20. Furthermore, if you receive only 70% bioavailability, this puts the cost at over $1.71. Since this is more likely the case, the cost is actually 3.5 times the cost of regular Sinement. If you are a young person getting only 44% bioavailability the cost comparison makes the CR priced at $2.73. This is 5.5 times the cost of regular Sinemet. If you are paying for your meds out of your own pocket, I hope I have given you something to think about. There is the arguement that maybe the patient was getting too much levodopa from the two 25/100 regular tablets. If the analysis is done based on a levodopa yield of .7 from the regular Sinemet (cut in half, cut a half in half to get .75) the numbers come out the same. Happy CRing or is it CRying! I should state the advantages of CR: 1. A more level release of levodopa is better then the bang, bang that is experienced with two regular. Over the long run doctors have guessed that the bang, bang may be harmful. 2. The patient only takes drugs every 5 or 6 hours as compared to every three hours. Patients, of which I am one, do not like to take tablets frequently. 3. Your doctor may say it is important you stay on the leading edge of drug therapy. Who is telling this to the doctor? Patients or Pharm Sales? Regards, Alan Bonander