mer is a suitable water soluble polymer, or slightly water soluble polymer or combination of both soluble and insoluble types such as sodium carboxymethylcellulose, hydroxethylcellulose, ethylhydroxcycellulose, natural gums (sodium carrageenan, gum tragacanth), ethylene oxide polymers, copolymers of methyl vinyl ether and maleic anhydride, or the like.