Should Hypurin Porcine Isophane (porcine insulin) cartridges be refrigerated once in use?

No, Hypurin Porcine Isophane (porcine insulin) cartridges must not be refrigerated in use or frozen; chemical and physical stability is demonstrated for 28 days at 25°C, but opening risks microbial contamination, aseptic handling is necessary, and in-use storage times and conditions are the user's responsibility.