Methylphenidate: Notice any difference between Generic manufactures/suppliers of methylphenidate...

Hi, Gail!
While all generic medications contain the same amount of the active drug you're right... each manufacturer's formulation may be different from other generics and the name brand. Some people don't tolerate these inactive ingredients (binders, fillers, colouring agents) well.
Off the cuff suggestion: Find yourself a little Mom and Pop drugstore who may have your favorite in stock or are much more likely to submit a special order for you if needed. The "big" stores are bound by company policy whereas the small shops are more geared to the patient's needs.
Regards and good luck!
Wildcat