Abstract: Water-soluble, biodegradable polymeric materials are provided for skin, hair and cosmetic use comprising the formula: ##STR1## wherein A is a water soluble, biodegradable polymeric material containing a radical selected from the group consisting of hydroxy, amino, imino, thio and carboxy;X is ##STR2## R.sup.1 is H, --OH, --CN(=nitrile), halogen or C.sub.1 -C.sub.4 alkyl; R.sup.2 is a saturated or unsaturated, at least bivalent hydrocarbon radical optionally substituted with one or more substituents selected from the group consisting of hydroxy-, amino-, C.sub.1 -C.sub.8 alkyl-, C.sub.1 -C.sub.8 alkoxy- and hydroxyalkyl groups which may be optionally substituted with one or more moieties selected from the group consisting of --CO--, --O--C(O)--O--, --C(O)--O--, --O--, --O--C(O)--, --S--, --NR.sup.4 --, --NH--C(O)--and --NH--C(O)--NH--;Y is a connecting link to the main chain of the hydrocolloid A selected from the group consisting of --O--, --O--C(O)--, --C(O)--O--, --NH--C(O)-- and --C(O)--NH;R.sup.3 and R.

Abstract: Composite crystals of alkali metal silicate, particularly hydrated sodium metasilicates such as sodium metasilicate pentahydrate with sequestering agents, are formed by co-crystallization of liquors that contain both alkali metal silicate and sequestering agents.