Which insulin type is typically cloudy in appearance?

Which insulin type is typically cloudy in appearance?

• A. Regular
• B. NPH
• C. Degludec
• D. Lispro

Answer: (B)

In insulin preparations, appearance distinguishes form: clear solutions versus cloudy suspensions. Cloudy looks come from suspended particles rather than a fully dissolved solution. NPH insulin is formulated as a protamine-containing suspension to delay absorption, so it appears cloudy. The other insulins mentioned are formulated as clear solutions, so they should look transparent. Therefore, the insulin type that is typically cloudy is the intermediate-acting NPH. When using cloudy insulin, gently roll or invert the vial to resuspend the particles before drawing up a dose, rather than shaking vigorously.

In insulin preparations, appearance distinguishes form: clear solutions versus cloudy suspensions. Cloudy looks come from suspended particles rather than a fully dissolved solution. NPH insulin is formulated as a protamine-containing suspension to delay absorption, so it appears cloudy. The other insulins mentioned are formulated as clear solutions, so they should look transparent. Therefore, the insulin type that is typically cloudy is the intermediate-acting NPH. When using cloudy insulin, gently roll or invert the vial to resuspend the particles before drawing up a dose, rather than shaking vigorously.