Which insulin component in Novolin 30/70 typically has the longest duration?

Which insulin component in Novolin 30/70 typically has the longest duration?

• A. Regular insulin
• B. Isophane insulin
• C. Both have the same duration
• D. Neither has a duration longer than 8 hours

Answer: (B)

In premixed insulins, one part provides quick, mealtime coverage while another supplies longer background insulin. Novolin 30/70 combines 30% regular insulin (short-acting) with 70% isophane insulin (NPH, intermediate-acting). Regular insulin starts within 30–60 minutes, peaks around 2–4 hours, and lasts about 5–7 hours. Isophane insulin begins later but lasts much longer, with activity roughly 14–24 hours. So the component with the longest duration is isophane insulin, giving extended effect between meals and overnight. This contrasts with regular insulin, which has a shorter duration, and confirms that at least part of the mix provides coverage beyond 8 hours.

In premixed insulins, one part provides quick, mealtime coverage while another supplies longer background insulin. Novolin 30/70 combines 30% regular insulin (short-acting) with 70% isophane insulin (NPH, intermediate-acting). Regular insulin starts within 30–60 minutes, peaks around 2–4 hours, and lasts about 5–7 hours. Isophane insulin begins later but lasts much longer, with activity roughly 14–24 hours. So the component with the longest duration is isophane insulin, giving extended effect between meals and overnight. This contrasts with regular insulin, which has a shorter duration, and confirms that at least part of the mix provides coverage beyond 8 hours.