Transitest: a technetium-99m labeled marker for determination of gastrointestinal transit. An estimate of the labeling stability.

Transitest is a formulation of pellets which can be labeled with the radioisotope technetium-99m. Transitest has been proposed as a marker for determination of gastrointestinal transit using a gamma camera. The labeling stability was estimated. Isotonic saline, gastric, and intestinal juice were added to labeled pellets from each of three different batches. Later on the activity was measured in the particulate and the liquid phases. One subject ingested a suspension of labeled pellets. Afterwards scintigraphy of the thyroid and the abdominal region was performed. Simultaneously the activity was measured in the collected urine. The labeling was so unstable that Transitest cannot be recommended as a marker if quantitative results are required.