i admit to being ignorant of the biochemistry here, but the little satanic cynic on my shoulder is whispering in my ear- what if, in the main, slow release of a drug is generically controlled via molecular packaging (liposomal, or some other surface reactant which slows release)- so for many drugs, you could take them in their direct form and direct release, or you could take them in their packaged form, which slows release down (@ a factor of 7?)- because, if this were true, this would explain the re-release of drugs in slow release form (which i presume leads to re-patenting, which i know is worth $100 mills. for big label drugs)- the cynical release, then, would be optimally timed for re-patenting: i.e. waiting for initial sales spike to plateau, then releasing slow release version to reinvigorate sales- i had wondered if this was the case with EPO- which made bazillions as a one-a-day, then was switched to aranesp, which is once weekly- in other words, why aren't many drugs initially released as slow release, other than the cynical reasoning above?