We have good experience for cap molds for medical use or food packaging use.
Eye dropper cap usually diameter 21mm, with tamper proof ring, can be motor de-screwing, gear de-screwing or force ejection.
Mold steel:
Cavity: FS136 China or S136 Sweden
Core : 9Cr18 China
Moving block insert: VIKING, Sweden
Mold base : stainless steel or P20 steel
Mold cavity number : 8 , 12, 16, 24, 32 avaliable
Runner : hot runner or cold runner as you wish
Hot runner brand: Mobest China, or YUDO Korea, or European brands.