Use of Share Capital

Good morning sir,

I just finished the last chapter of your lecture and have a question towards the use of share capital. One of the purpose provided by lecture note is that it can support the premium payable on the redemption of shares or debentures. Although I understood the double entry for the redemption account, I am confused why we should credit share premium because by definition share premium is non-distributable.

Many thanks for your time!

Regards,

Chen