Your search for "effervescent tablet" revealed the following:

Sale price £49.00 Regular price £70.00 Sale
Sale price £29.38 Regular price £40.00 Sale
Sale price £36.99 Regular price £40.00 Sale
On Sale from £70.66 Regular price £90.00 Sale
Sale price £68.95 Regular price £90.00 Sale
Sale price £69.75 Regular price £90.00 Sale
Sale price £49.99 Regular price £70.00 Sale
Sale price £25.95 Regular price £33.00 Sale
Sale price £39.70 Regular price £50.00 Sale
On Sale from £90.90 Regular price £110.00 Sale
On Sale from £39.99 Regular price £50.00 Sale