Radiosynthesis of ^99MTc-Montelukast as a Novel Potential Radiopharmaceutical Model for Lung Scanning

Montelukast, a leukotriene receptor antagonist with a high affinity and selectivity for the cysteinyl leukotriene receptor type-1, was radiolabeled with ^99mTc using a direct tagging procedure. The processing parameters—amounts of both montelukast and reducing agent, pH of the reaction mixture, reaction temperature, time of reaction, and in vitro stability of the ^99mTc-montelukast complex—were thoroughly investigated. The ^99mTc-montelukast complex had a percent radiolabeling yield of 92 ± 0.23 and an in vitro stability of 6 hours. According to biological distribution studies, the maximum uptake of ^99mTc-montelukast complex for the lungs was 35.89 ± 1.03 % injected activity/gm tissue at 15 minutes following injection and remained high in the lungs for another hour (15.88 ± 0.39%), whereas the washout of mice organs appeared to primarily occur via the urinary tract. Because the ^99mTc-montelukast complex is not a blood product, it is safer. To summarize, the ^99mTc-montelukast complex is a new radiopharmaceutical that might be utilized for perfusion imaging of the lungs that is both safer and more useful.