Instant 99mTc-labelled glucoheptonate kit for kidney imaging

Area of Science:

• Radiopharmacy
• Nuclear Medicine
• Analytical Chemistry

Background:

• Technetium-99m glucoheptonate (99mTc-GH) is a radiopharmaceutical used in nuclear imaging.
• Optimizing the preparation of 99mTc-GH is essential for ensuring high labeling yield and complex stability.
• Previous methods may have stability issues affecting clinical use.

Purpose of the Study:

• To investigate and optimize the preparation of 99mTc-GH.
• To determine optimal conditions for high labeling yield and complex stability.
• To evaluate the impact of pH adjustment methods on 99mTc-GH stability.

Main Methods:

• Gel chromatography column scanning was employed to analyze fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate, and 99mTc-chelate.
• Radiochemical yield and stability were assessed under varying concentrations of glucoheptonic acid-calcium salt and stannous chloride dihydrate (SnCl2.2 H2O).
• The effect of pH adjustment using sodium hydroxide versus an alternative method was evaluated.

Main Results:

• A stable, high labeling yield of 99mTc-GH was achieved using 40-50 mg glucoheptonic acid-calcium salt and ≥0.45 mg SnCl2.2 H2O at pH 6.5-7.0.
• Sodium hydroxide for pH adjustment negatively impacted complex stability.
• An alternative pH adjustment procedure yielded a stable 99mTc-GH complex suitable for injection.
• Organ distribution and blood clearance in rabbits were comparable to previous reports.
• Renal concentration studies in normal subjects showed satisfactory results.

Conclusions:

• Optimal concentrations of glucoheptonic acid-calcium salt and SnCl2.2 H2O, along with precise pH control, are critical for producing stable 99mTc-GH.
• The method of pH adjustment significantly influences the stability of the 99mTc-GH complex.
• The developed preparation method ensures a stable radiopharmaceutical for diagnostic imaging, with satisfactory renal uptake observed.