No-deal Brexit: Disruption at Dover 'could last six months' per BBC News who muddy the waters of on medicines

Read this part of this BBC article 

https://www.bbc.co.uk/news/uk-politics-46480374

'Current advice is that there should be a six-week stockpile of medicines in the UK to cover the possibility of disruption after a no deal Brexit.

About 90% of medicines imported by the UK and the Republic of Ireland come in through Dover.'

So what proportion of medicines are imported as opposed to produced in the UK? Will this "disruption" affect 90% of 90%? Or 90% of 10%? What is the truth, and why don't I trust the Remoaners at the BBC to tell me the truth?