This is called “Special English” aka “Simple English” or “Voice of America English”. It is meant to be very clear and straightforward to understand to minimize the possibility of miscommunication and make it so that non-experts of all backgrounds can take away the important messages. Given how important the medicine supply chain is to lots of people’s daily lives, I’m sure they didn’t want this page to seem understandable only by the educated.
https://en.m.wikipedia.org/wiki/Special_English