This trial is a randomized, double-blind, single-center, single-dose escalating Phase I clinical trial designed to evaluate the safety, tolerability, and pharmacokinetic characteristics of injectable GMDTC in healthy subjects

The primary objective of this study is to evaluate the safety and tolerability of a single dose of injectable GMDTC in healthy subjects and to determine the maximum tolerated dose (MTD). The secondary objective is to evaluate the pharmacokinetic characteristics of injectable GMDTC after a single dose in healthy subjects and its impact on cadmium levels in the body.The modified Fibonacci method (also known as the Fibonacci dose escalation method) was used for dose escalation, with six predetermined dose groups.

Inclusion Criteria:

• Age ≥18 years, both male and female are eligible;
• Male subjects must weigh at least 50.0 kg and female subjects must weigh at least 45.0 kg, with a body mass index (BMI) between 19 and 26 kg/m2, including the critical value;
• Subjects must voluntarily sign a written informed consent form.

Exclusion Criteria:

• past or current clinical significant diseases that affect the circulatory, endocrine, nervous, digestive, respiratory, renal, hematological, immunological, psychiatric, and metabolic systems or any other disease or symptom that may interfere with the study results;
• eGFR<90 mL/min/l.73 m2 during screening (eGFR calculated using the Cockcroft-Gault formula: eGFR (mL/min/1.73 m2) =*(140-age)weight (kg)/[0.818Cr (umol/L)]*0.85 (female));
• urine creatinine (Cr) > 5 umol/mol for two consecutive days during screening (with a creatinine concentration of≥0.3 g/L and ≤3 ug/L);
• a history of allergy to drugs, food, or other substances, especially to the components of the study drug;
• undergone or planned surgery that affects drug metabolism and safety assessment within 4 weeks before screening;
• use of any medication or health supplements (including Chinese herbal medicine) within 14 days before screening;
• participated in any clinical trial and used any investigational drug within three months before screening;
• blood donation or significant blood loss (≥200 mL, excludingmenstrual bleeding in women) within 3 months before screening, blood transfusion, or use of blood products;
• inability to tolerate venipuncture and/or history of fainting or needle phobia;
• pregnant or lactating women, and subjects who cannot adopt effective non-drug contraceptive measures during the study period;
• unable to adopt contraceptive measures within 6 months after the end of the study;
• have special dietary requirements and cannot adhere to a uniform diet;
• daily consumption of excessive tea, coffee, and/or caffeine-containing beverages (more than 8 cups, 1 cup - 250 mL);
• unable to stop using any tobacco products during the study period;
• alcoholics or frequent drinkers within 6 months before screening, i.e., drinking more than 14 units of alcohol per week (1 unit - 360.5 mL of beer or 45 mL of 40% alcohol or 150 mL of wine) or unable to stop using any alcohol-containing products during the study period;
• drug abusers or those who used soft drugs (such as marijuana) within 3 months before screening or used hard drugs (such as cocaine, benzoyl peroxide, etc.) within 1 year before screening;
• clinically significant abnormalities in vital signs, physical examination, electrocardiogram, electroencephalogram, cardiac ultrasound, abdominal ultrasound, chest CT, ophthalmic examination, or laboratory tests (as judged by the clinical research physician)

This clinical study is a double-blind study, in which participants such as clinical researchers, project managers, and project monitors are unaware of the random coding and drug administration groups of the subjects. Non-blind monitoring during the clinical study will be conducted by non-blind monitors. In addition, drug preparation will be carried out by non-blind researchers independent of this study. Analysis and testing personnel will also adopt blind analysis.