Tb161RadioligandQualityChecker

Tb-161 Radioligand Quality Checker — Quality control of Tb-161 radioligand

ℹ️ Utility checks critical parameters of Tb-161 Radioligand:

• Radiochemical purity (≥95%)
• Free terbium (≤2%)
• Tb-160 impurity (<0.01%) — CRITICAL!
• Specific activity, pH, endotoxins, sterility

⚠️ CRITICAL: Tb-160 (T½=72.3 days) creates long-term radiation burden!

Tb-161 emits beta particles and low-energy Auger electrons, making it ideal for micrometastases.

Terbium chemistry is similar to lutetium but requires control of specific impurities.

Usage

Tb161RadioligandQualityChecker.exe → demo mode (console output)

Tb161RadioligandQualityChecker.exe input.csv output.json → evaluate your data

Input format

BatchNumber,RadiochemicalPurityPercent,FreeTerbiumPercent,PrecursorPercent,SpecificActivityGBq_per_mg,pH,ResidualSolventsPPM,EndotoxinsEU_per_mL,SterilityTest,ActivityMBq,RadionuclidicPurityPercent,Gd160ImpurityPercent,Tb160ImpurityPercent

Example

TB161-LIG-2026-001,99.0,0.5,0.05,30.0,5.5,100.0,10.0,0,500.0,99.95,0.0001,0.0005

— WHY IS THIS NEEDED?

Tb-161 is promising theranostic isotope, alternative to Lu-177.

• Emits medium-energy beta particles and large number of Auger electrons.
• Auger electrons have very short range (nanometers), allowing destruction of single cancer cells with minimal damage to surrounding tissues.
• Half-life 6.89 days.
• Produced by neutron activation of enriched Gd-160 in reactor.

⚠️ CRITICAL:

• Radiochemical purity ≥95% — guarantee of specific binding to target.
• Free terbium ≤2% — free ions accumulate in bones and liver.
• Tb-160 impurity <0.01% — Tb-160 is long-lived and creates unnecessary radiation burden.
• Gd-160 impurity <0.001% — stable target isotope, must be removed during purification.
• Specific activity must be high for effective targeting.
• pH 4.5-6.5 — optimal media for Tb-DOTA complex stability.
• Residual solvents must be minimal (<500 ppm).
• Endotoxins <175 EU/mL — standard for parenteral drugs.
• Sterility — MANDATORY.

Key features

• Strict control of Tb-160 impurity characteristic of reactor production.
• Assessment of residual precursor, critical for therapy efficacy.
• Specific activity check for effective targeting.
• Compliance with GMP requirements for new theranostic radiopharmaceuticals.
• Comprehensive safety check (endotoxins, sterility, pH, solvents).

Critical parameters

• Radiochemical purity: ≥95.0%
• Free terbium: ≤2.0%
• Precursor residue: <0.1%
• Specific activity: ≥20.0 GBq/mg
• Radionuclidic purity: ≥99.9%
• Tb-160 impurity: <0.01%
• Gd-160 impurity: <0.001%
• Residual solvents: <500 ppm
• pH: 4.5–6.5
• Endotoxins: <175 EU/mL
• Sterility: no growth

💡 Usage tips:

1. Radiochemical purity determined by TLC or HPLC.

2. Tb-160 impurity controlled by gamma spectrometry.

3. Synthesis usually performed on automatic modules or manually using kits.

4. Drug is stable for several days due to strong DOTA complex.

5. Tb-161 also emits gamma quanta, allowing post-therapeutic imaging.

⚠️ Note: Tb-161 represents next generation of theranostics after Lu-177. Its unique combination of beta radiation and Auger electrons makes it especially effective against micrometastases that often escape Lu-177 therapy. Quality control here is critical as any error can reduce advantage of this complex mechanism of action.