Question

Whether insulin can be orally administered to diabetic people or not.why?

Answer 1

No insulin cant be given to diabetic person as it dosent work fastly becuse it needs difussion as fast as it can or otherwise it may lead to problem or further deadth can also occur. So it is directly injcted to blood stream

Answer 2

No, It is because of the peptide nature of the hormone,
you know our stomach has an acidic pH and it is a site of protein digestion so if you will administer insulin via oral route it will be degraded once reaching into the stomach and won't teach it's Target.
Subcutaneous or infusion mode of it's administration makes it reach it's target in an active form.

hope this helps!