Your search for "effervescent tablet" revealed the following:

Sale price £36.70 Regular price £44.00 Sale
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Sale price £36.49 Regular price £50.00 Sale
Sale price £69.77 Regular price £90.00 Sale
Sale price £69.99 Regular price £90.00 Sale
Sale price £48.89 Regular price £60.00 Sale
Sale price £22.56 Regular price £30.00 Sale
Sale price £134.76 Regular price £150.00 Sale
Sale price £67.80 Regular price £90.00 Sale