Is Methylin exactly the same as Methylphenidate (Ritalin)?

methylin is a short acting brand of methylphenidate, so is ritalin. Both are brand names, methylin by Alliant pharmaceuticals, ritalin by Novartis. Both come in long acting forms which would be distinguished by adding LA, SR or CR or something like that to the name. So if no extra letters, both are short acting methylphenidate and should be interchangeable. They are not identical, since they may have different non active pill components and such which might affect absorption rates, but should be close enough to make no difference to most users.