Preparation of 99mTc-Nanocoll for use in sentinel node localization: Validation of a protocol for supplying in unit-dose syringes.

Objectives: To determine if 99mTc-Nanocoll is affected by storage in a syringe, passage through an R-Lock or mixing with Patent Blue V dye.

Methods: A Nanocoll kit was reconstituted at 280 MBq/5 ml. Samples of 0.5 ml were drawn into 3 ml Plastipak syringes. After 1 h and 6 h, adsorption of 99mTc on a syringe was measured and the following tests of quality were performed on samples from the kit and a syringe: 99mTc-pertechnetate impurity by thin-layer chromatography, the percentage of 99mTc on particles >100 nm by Nuclepore filtration and particle size by photon correlation spectroscopy. These tests were also applied to samples that had been passed through an R-Lock or mixed with Patent Blue V. Each experiment was performed five times.

Results: In all samples, adsorption of 99mTc on syringes was <1%, 99mTc-pertechnetate impurity was <2%, >95% of 99mTc was labelled to particles <100 nm in diameter, the mean particle diameter was 6.6 nm and the particles had a diameter of <12 nm. All tests showed no significant difference (P > 0.05, n = 5) between 99mTc-Nanocoll from the original kit and a syringe at either 1 h or 6 h. Similar results were obtained with samples that had been passed through an R-Lock or mixed with Patent Blue V.

Conclusions: A capped 3 ml Plastipak syringe is a suitable container in which to supply 99mTc-Nanocoll. Neither passage through an R-Lock nor mixing with Patent Blue V affects the quality of 99mTc-Nanocoll.