GI testing made simple
do away with the need to duplicate the results of in vitro
experiments in animals.
Researchers at Rohm and Haas have developed a new system for gastrointestinal dissolution testing that potentially could do away with the need to duplicate the results of in vitro experiments in animals.
When developing a new drug, it is important to demonstrate that the in vitro dissolution tests are predictive of the behaviour of the formulation in vivo - a process known as in vitro in vivo correlation or IVIVC.
The new system involves the use of three separate, stirred chambers that represent the gastric, intestinal and systemic environments in the body. The tablet dosage form is added to the gastric chamber containing simulated gastric fluid, and a dip tube allows solution and fine solids to transfer to the intestinal cell. This simulates the in vivo transfer of undissolved solids from the stomach to the intestine.
Dissolution continues in the simulated intestinal chamber, and then the fluid is passed through a filter so that only dissolved drugs can enter the systemic cell. The system has been tested using four different drugs - ibuprofen, pseudoephedrine, paracetamol and diclofenac - and the results indicate a close correlation with regard to in vivo absorption kinetics, even across dosage forms.
Dr Lynn Hughes, senior scientist, process solutions at Rohm and Haas, told In-Pharmatechnologist.com that the technique is currently being evaluated as a research tool, and has not been validated enough to form part of the standard quality control armamentarium. However, the hope is that in time it could provide a means of reliably predicting whether dissolution parameters seen in the test tube will occur in the body.
If this proves to be the case, researchers could skip straight from in vitro experiments into man, reducing costs, time to market and the number of animals needed to conduct the preclinical research.
One issue that Rohm and Haas need to sort out relates to the commercialisation of the technology. It will not be sold as a piece of equipment and so would require some form of licensing structure. This will bring its own problems to bear in terms of monitoring use of the system.
