Abstract
Dissolution behavior of 2 kinds (A and B) of Nifedipine (NF) sustained-release preparations were investigated. Dissolution rates were measured by the J. P. X dissolution test procedure in pH 1.2, 3.0, 4.0, 5.0, and 6.8 solutions, which contained various amounts of Tween 80.
The following results were obtained: The release from the sample A was pH-independent, but was much effected by wet. The addition of 0.125% of Tween 80 to the solution caused 50% increase of the release from the sample A. The sample B showed pH-dependent release, and was found to be composed of 40% of rapid-release granules and 60% of enteric and sustained-release one.
