Inderal-LA (propranolol long-acting)
''...controlled release oral formulation comprising coated spheroids of propranolol or a pharmaceutically acceptable salt thereof, each spheroid coated with a mixture of 80 to 100% by weight of ethylcellulose, preferably having a viscosity of 50 cps at 20° C., 20 to 0% by weight of hydroxypropyl methylcellulose and optionally up to 20% plasticizer based on the total weight of the membrane. These spheroids prior to membrane coating comprise 40 to 65% by weight propranolol or a pharmaceutically acceptable salt thereof and 35 to 60% by weight of microcrystalline cellulose and are prepared by extrusion and spheronization. The ratio of ethylcellulose to hydroxypropylcellulose and coating thickness depend upon the desired controlled release characteristics.''
So basically the extended release mechanism is in the matrix of the pill so the thicker the propranolol spheroid, the longer it takes to digest. But they will mix in with the binders and fillers, so you won't be able to see the individual spheroids.
I can't find it anywhere, but I think if you cut the pill in half it will still maintain the LA release mechanism, but if you crush the pill, it would destroy it, much like OC. (just an educated guess)
As far as the Ritalin-LA, it works differently than the Ideral-LA:
''Ritalin-LA the most recent addition to the group of long-duration stimulant drugs, received FDA approval in early 2002. Like
Metadate CD, each capsule contains a mixture of beads, 50% of which are designed to immediately release methylphenidate, with the remaining 50% providing a second, delayed release of the active drug."
So crushing the beads will turn the Ritalin-LA into Ritalin IR, much like with Adderall XR.
So every drug is different. Not all the XR/CD/ER/SR/LA formulations are the same...
hope this helps!
-cap
