Your search for "effervescent tablet" revealed the following:

Sale price £42.57 Regular price £70.00 Sale
Sale price £96.30 Regular price £130.00 Sale
Sale price £35.99 Regular price £40.00 Sale
On Sale from £22.79 Regular price £30.00 Sale
Sale price £53.99 Regular price £70.00 Sale
On Sale from £39.76 Regular price £50.00 Sale
Sale price £98.88 Regular price £130.00 Sale
Sale price £109.99 Regular price £130.00 Sale
Sale price £104.99 Regular price £150.00 Sale
Sale price £399.96 Regular price £540.00 Sale
Sale price £49.99 Regular price £70.00 Sale