ls, carboxymethyl cellulose, plant exudates such as acacia, ghatti, and tragacanth, seaweed extracts such as sodium alginate, propylene glycol alginate and sodium carrageenan, and Ucare JR-polymer (a cationic modified hydroxyethyl cellulose available from Union Carbide). preferred as the optional additional thickener for the present vehicle systems are natural polysaccharide materials.