@Klaudia I don’t think so I shook it for a good minute or two
Contact the company just in case!
Looks like fat....
It’s probably the gaviscon formed a clump. A bit like putting gravy mix in water it needs a stir. I used to stir it in with a sterilised spoon to get rid of the lumps when I put in the gaviscon x
Could it possibly be be from not shaking the bottle properly for the powder to mix with the hot water