Your search for "effervescent tablet" revealed the following:

Sale price £144.50 Regular price £200.00 Sale
Sale price £29.54 Regular price £40.00 Sale
Sale price £44.99 Regular price £50.00 Sale
Sale price £44.87 Regular price £50.00 Sale
Sale price £28.45 Regular price £40.00 Sale
Sale price £55.95 Regular price £70.00 Sale
Sale price £143.15 Regular price £200.00 Sale
Sale price £69.77 Regular price £90.00 Sale