Expert: Dr. Ravindra Bhaskar Ghooi - 7/23/2007

Question
what is the difference between time release, control release, delay release, sustained release, extendeded release formulation ?

Answer
Hi Katie,
The release of a drug from the tablet depnds uon disintegration and dissolution of the drug and the coatings over the drug. Often we want to modify the disintegrationa dn dissolution and hence the release of the drug. For this we modify the coating or add substances in the matrix of the tablet which dissolve very slowly. This is controlling the release and any tablet with such a mechanism is known as a contrlled release. In some controlled release tablets we delay the release to a required schedule, then we call it sustained release, or delayed release.
Thus all tablets with modified release are controlled release tablets. in some we have delayed release, and in some timed release. There are situations where we do not want the release to take place in the stomach but in the intestine, there we add a pH dependent coating and it is known as enteric coating. All these are forms of controlled release.
Some companies use the term controlled release while others call it sustaned or delayed release.
Ravi Ghooi