Meaning
Aqueous solutions that mimic the pH and enzymatic composition of the human stomach and intestines are used to study the release of substances from polymers. These mixtures allow labs to conduct safety tests without using animal or human subjects. Using simulated gastrointestinal fluid provides a standardized environment for measuring the bioaccessibility of additives.
The results help determine if a chemical is likely to be absorbed by the body.
Chemical Composition
Specific salts and acids are combined to reach a target pH level. Because simulated gastrointestinal fluid often contains pepsin or pancreatin, it reproduces the chemical breakdown of food.
Dissolution Environment
The plastic sample is submerged in the liquid and agitated at body temperature. During the test, simulated gastrointestinal fluid extracts molecules from the polymer surface and matrix. This process is monitored over several hours to match the typical residence time in the gut.
The concentration of the migrant in the fluid is then measured using high resolution chromatography. Variations in the fluid composition can simulate the differences between a fasted and a fed state.
Test Outcome
Data from these experiments show the percentage of an additive that becomes available for absorption. Findings using simulated gastrointestinal fluid are used to set migration limits for new packaging materials. Ensuring that the resin is resistant to these fluids protects the consumer from unintended chemical exposure.
