[1-(11)C]palmitic acid: improved radiopharmaceutical preparation

Area of Science:

• Radiochemistry
• Nuclear Medicine

Background:

• Positron emission tomography (PET) relies on radiotracers for in vivo imaging.
• [1-(11)C]palmitic acid is a valuable PET tracer for studying fatty acid metabolism.
• Efficient and reliable synthesis of [1-(11)C]palmitic acid is crucial for clinical use.

Purpose of the Study:

• To describe a simple and efficient synthetic procedure for routine preparation of [1-(11)C]palmitic acid.
• To develop a processing system for facile separation of the target radiotracer.
• To provide a method for producing high-purity [1-(11)C]palmitic acid suitable for human administration.

Main Methods:

• Carbonation of n-pentadecylmagnesium bromide with [11C]carbon dioxide.
• Development of a processing system for separation of [11C]palmitic acid from Grignard reaction by-products.
• Optimization of reaction conditions for yield and purity.

Main Results:

• A simple synthetic procedure and processing system were established.
• Facile separation of [11C]palmitic acid from radiolabeled and unlabeled by-products was achieved.
• Yields of 1.85-2.78 GBq (50-75 mCi) of pure, sterile, pyrogen-free [1-(11)C]palmitic acid were obtained from 7.40-9.25 GBq (200-250 mCi) of [11C]CO2 within 30 minutes.

Conclusions:

• The described method provides a robust and efficient way to prepare [1-(11)C]palmitic acid.
• The synthesized [1-(11)C]palmitic acid meets the stringent requirements for human use in PET imaging.
• This improved synthesis facilitates the routine clinical application of [1-(11)C]palmitic acid PET studies.