Development of a new dissolution test method for an oral controlled release preparation, the PVA swelling controlled release system (SCRS).

In vitro dissolution tests of novel controlled release tablets, the poly(vinyl alcohol) (PVA) swelling controlled release system (SCRS), were performed by various methods under different conditions in the sinking state in water. The in vitro release profiles of various tests were almost the same and faster than the in vivo absorption profiles calculated from the plasma drug concentrations of humans. A novel dissolution test method was developed considering the gastrointestinal tract (GI) conditions. PVA particles were used as the filler in a flow-through cell. PVA particles swelled with water were put in the flow-through cell and the tablet was buried in PVA. The test medium was dropped from the top of the cell, and the dissolution medium that dripped from the bottom of the cell was collected and assayed. The in vitro dissolution profile determined by this method was similar to the in vivo absorption profile against other in vitro methods in the sinking state in water. Furthermore, a good correlation between in vitro and in vivo for the two different release rate preparations was obtained using a flow pattern imitating the GI transition.