A coating composition for medicaments comprises a solid pharmaceutical extending medium and from about 10 to 40% (by weight of the total weight) of a water-soluble, non-toxic cationic salt of a "cellulose hydrogen dicarboxylate," which is defined as a cellulose ester of an aromatic or aliphatic dicarboxylic acid in which only one of the carboxylic acid groups is esterified, the other remaining free.  Preferably, the cellulose derivatives also contain other ester groups formed by the acylation of other hydroxy groups of the cellulose with a monocarboxylic acid acylating agent, preferably having from 1 to 6 carbon atoms. Preferred compounds of this type are the alkali metal, alkaline earth metal and organic base, e.g. triethanolamine and piperidine, salts of cellulose acetate phthalate. Ether groups, e.g. ethoxy and propoxy, may also be present.  The extending medium may be lactose (preferred), mannitol, sucrose, starch or glycine.  The compositions may also contain up to about 10% by weight of conventional pharmaceutical binders, e.g. sodium alginate, propylene glycol alginate, acacia gum, tragacanth or hydrolysed starch paste, and from about 0.5 to 2% of a pharmaceutical lubricant, e.g. magnesium stearate or stearic acid.  Plasticizers which are conventionally used in pharmaceutical preparations may also be present.  The examples relate to compositions comprising the triethanolamine, piperidine and calcium salts of cellulose acetate phthalate and the potassium salt of cellulose propionate phthalate. The diluents or excipients mentioned in the examples include glycerine, mannitol, sodium carboxymethylcellulose, gelatine, lactose, magnesium stearate and sodium alginate. Specification 526,276 is referred to.ALSO:An enteric press-coating composition comprises a solid pharmaceutical extending medium and from about 10 to 40% by weight of the total weight of a water-soluble, non-toxic, cationic salt of a "cellulose hydrogen dicarboxylate" which is defined as a cellulose ester of an aromatic or aliphatic dicarboxylic acid in which only one of the carboxylic acid groups is esterified, the other remaining free.  Preferably these derivatives also contain other ester groups formed by the acylation of other hydroxy groups in the cellulose with a monocarboxylic acid acylating agent preferably having from 1 to 6 carbon atoms.  Preferred compounds of this type are the alkali metal, alkaline earth metal, and organic base, e.g. triethanolamine and piperidine salts of cellulose acetate phthalate. Such compounds may also contain other ester groups, e.g. propyl, butyl, or may additionally contain ether groups, e.g. ethoxy, propoxy.  The extending medium may comprise solid, compressible fillers, e.g. lactose (preferred), manitol, sucrose, starch, glycine. Up to about 10% by weight of the total weight of conventional pharmaceutical binders, e.g. sodium alginate, propylene glycol alginate, acacia, tragacanth, hydrolysed starch paste, and from about 0.5 to 2% of a pharmaceutical lubricant, e.g. magnesium stearate, stearic acid and conventional pharmaceutical plasticizers may also be present. The composition may be granulated and used in a conventional press coating machine.  An example of such a composition comprises, triethanolamine cellulose acetate phthalate 15 parts by weight, lactose 82 parts, glycerine 1 part, sodium carboxyl methyl cellulose 1.25 parts, magnesium stearate 0.75 parts. Specification 526,276 is referred to.