Following the previous study, which investigated the pharmacological properties of the Technekitty injection (Tc-99m), the toxicity of a single intravenous administration of the Technekitty injection (Tc-99m) and the side effects that may occur at the diagnostic dose were confirmed. The Technekitty injection (Tc-99m) was administered intravenously once at a dose of 0, 0.67, 2.0, and 6.0 mCi/kg to 5 male and female rats per group. Mortality, general symptom observation, and weight measurement were performed for 2 weeks, followed by observation of autopsy findings. There were no deaths, and no statistically significant weight change was observed. No abnormal systemic signs related to the Technekitty injection (Tc-99m) were observed. These results confirmed that Technekitty injection (Tc-99m) can be safely administered intravenously at doses up to 6.0 mCi/kg. Additionally, technetium-99m at an average dose of 2 mCi (74 MBq) has been verified as a diagnostic dose without adverse effects, allowing the Technekitty injection (Tc-99m) to be used safely without side effects at this dosage. This study demonstrates that the Technekitty injection (Tc-99m) has a wide safety margin, supporting its potential for clinical application. Moreover, these findings align with the nonclinical safety standards for radiopharmaceuticals, reinforcing its utility in veterinary medicine. The Technekitty injection (Tc-99m) is expected to be applicable for clinical diagnosis as a veterinary drug in Korea.

Abstract
INTRODUCTION
MATERIALS AND METHODS
    시험방법 개요
    시험물질의 품질 확인 시험
    시험물질 조제 및 투여
    실험동물 사육 관리
    실험 설계
    관찰 및 측정
    부검
    통계 분석
RESULTS
    시험물질의 품질 확인 및 투여
    사망률
    일반증상
    체중
    부검 소견
DISCUSSION
SUPPLEMENTARY MATERIALS
References

• Jae Cheong Lim(Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Korea) Corresponding author
• So-Young Lee(Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Korea)
• Eun Ha Cho(Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Korea)
• Yu Mi Jung(Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Korea)
• Ki Hwan Park(Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Korea)
• Young Uk Park(Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Korea)
• Sung Soo Nam(Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Korea)
• Tae Hoon Lee(Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Korea)
• Jae Won Lee(Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Korea)
• Yiseul Choi(Korea Radioisotope Center for Pharmaceuticals, Korea Institute of Radiological and Medical Sciences, Seoul 01812, Korea)
• Inki Lee(Korea Radioisotope Center for Pharmaceuticals, Korea Institute of Radiological and Medical Sciences, Seoul 01812, Korea)
• Yeon Chae(Laboratory of Veterinary Internal Medicine, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea)
• Byeong-Teck Kang(Laboratory of Veterinary Internal Medicine, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea)