The present invention provides particulate denture cleansing compositions generally in tablet form containing a peroxygen compound and an effervescence generator, together with sufficient acid or alkali generally to obtain a pH of pH2 to pH 12. The peroxygen compound comprises an hydrated magnesium salt of a substituted peroxygen compound having the empirical (anhydrous) formula:
in which R o each represent hydrogen or both combine together to form an olefinic bond and R, and R 2 combine together with each other and the carbon atoms from which they depend to form a carbocyclic nucleus, which nucleus may optionally be further substituted by one or more of the functional groups selected from alkyl, carboxylate, percarboxylic acid, sulphonate, nitro, chloro and bromo groups; or in which R 1 and Ro each represent either hydrogen or an alkyl group and both R o combine together to form an olefinic bond; and n represents the number of carboxylate groups present in the compound, and is especially magnesium monoperoxyphthalate.
The effervescence generator is often a solid organic acid such as succinic acid together with sodium carbonate or bicarbonate and/or anhydrous sodium perborate. At higher pHs, the composition preferably contains a complexing agent like sodium citrate in order to ameliorate a detectable impairment in the rate of dissolution of the tablet.