Recombinant corticotropin (Shanghai Duomirui Biotech)

Primary objective: To study the safety and tolerability of single and multiple intramuscular administration of recombinant corticotropin for injection in healthy Chinese subjects and to determine the safe dose range. Secondary objectives: 1. To study the pharmacokinetic (PK) characteristics of the active ingredient rACTH after single and multiple intramuscular administration of recombinant corticotropin for injection in healthy Chinese subjects. 2. To study the pharmacodynamic (PD) characteristics of recombinant corticotropin for injection in healthy Chinese subjects after single and multiple intramuscular administration.