18F-labeled Bisphosphonate as an Alternative Candidate to the Gold Standard[18F]sodium fluoride ([18F]NaF) for PET Bone Imaging.

Bone metastases are a common source of malignancy in the skeleton and occur much more often than primary bone cancer. Several works were being performed to identify early markers for bone metastasis and novel drug targets to improve patients' quality of life. As some concerns exist with the [18F]sodiumfluoridein positron emission tomography (PET) bone imaging, there has been an increase in the number of targeted radiopharmaceutical markers for bone metastases imaging in its competitor, 68Ga. Since 18F properties are superior to those of 68Ga, there is a distinct motivation for developing 18F radiopharmaceuticals for bone metastases imaging.

Analytical GC-FID Method for the Determination of Organic Solvents in Radiopharmaceuticals.

BACKGROUND: Organic solvents play an indispensable role in most of the radiopharmaceutical production stages. It is almost impossible to remove them entirely in the final formulation of the product. OBJECTIVE: In this presented work, an analytical method by gas chromatography coupled with flame ionization detection (GC-FID) has been developed to determine organic solvents in radiopharmaceutical samples. The effect of injection holding time, temperature variation in the injection port, and the column temperature on the analysis time and resolution (R ≥ 1.5) of ethanol and acetonitrile was studied extensively. METHODS: The experimental conditions were optimized with the aid of further statistical analysis; thence, the proposed method was validated following the International Council for Harmonisation (ICH) Q2 (R1) guideline. RESULTS: The proposed analytical method surpassed the acceptance criteria including the linearity > 0.990 (correlation coefficient of R2), precision < 2%, LOD, and LOQ, accuracy > 90% for all solvents. The separation between ethanol and acetonitrile was acceptable with a resolution R > 1.5. Further statistical analysis of Oneway ANOVA revealed that the increment in injection holding time and variation of temperature at the injection port did not significantly affect the analysis time. Nevertheless, the variation in injection port temperature substantially influenced the resolution of ethanol and acetonitrile peaks (p < 0.05). CONCLUSION: The proposed analytical method has been successfully implemented to determine the organic solvent in the [18F]fluoro-ethyl-tyrosine ([18F]FET), [18F]fluoromisonidazole ([18F]FMISO), and [18F]fluorothymidine ([18F]FLT).