Dissolution testing gastrointestinal simulation

The second situation when IVIVC is not likely for class II drugs is where the absorption is limited by the saturation solubility in the gastrointestinal tract rather than the dissolution rate, as discussed in more detail above. In this situation, the drug concentration in the gastrointestinal tract will be close to the saturation solubility, and changes of the dissolution rate will not affect the plasma concentrationtime profile and in vivo bioavailability. Standard in vitro dissolution tests are carried out under sink conditions , i.e., at concentrations well below the saturation solubility. Thus, only effects related to dissolution rate can be predicted in vitro. If more physiologically relevant dissolution media are used, which do not necessarily provide sink conditions , the possibility for IVIVC could be improved, as has been indicated by the results of recent studies using simulated intestinal medium [76],... 

The dissolution test is conducted over a 7-h time period with aliquots of sample taken every hour. In contrast, diclofenac sodium is available in an extended-release form. The dissolution test is conducted over an 18-h period in which multiple samples are taken, with a change in the dissolution media to simulate a change from the stomach to the gastrointestinal tract. The purpose of dissolution testing is to ensure that the active ingredient is being released from the dosage form at an appropriate time. 

The oral mode of taking drugs has been quite prevalent and popular for ages. The basis of carrying out drug dissolution tests is to simulate the gastrointestinal tract, where... 

In Vitro Methods. In recent years, there has been great interest in the development of laboratory test systems that can simulate the disintegration and dissolution of a drug product in the human gastrointestinal... 

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