Health Queries about Mixtard 30 HM 100IU/ml Penfill (5*3ml Penfill Cartridge / Injection)

I currently use a premixed human insulin 50:50, and I'm looking for guidance on switching to insulin cartridge. Any suggestion?

This is important to get right - different premixed insulins vary in their NPH-to-soluble ratio, and moving from one ratio to another isn't a simple swap since ...