Formula

ZnO.

Derivation

Oxide of zinc is obtained by subjecting precipitated carbonate of zinc to a red heat, till the whole of the carbonic acid and water are expelled.

It is in the form of a yellowish-white powder, insoluble in water, but soluble in dilute sulphuric and hydrochloric acids, without effervescence. It is inodorous and tasteless.

Medical Properties And Action

Oxide of zinc is tonic and antispasmodic, but in large doses causes vomiting and purging; by gradually increasing the dose, large quantities can be taken without injurious effects. It should never be given on an empty stomach, as it may cause nausea.

Therapeutic Uses

It is employed in spasmodic asthma, convulsions of children, epilepsy, chorea, whooping-cough, hysteria, and is an excellent remedy for gastralgia ; also in chronic diarrhoea and chronic dysentery.

Dose

Of oxide of zinc, gr. ss to gr. x.

Dental Uses

Oxide of zinc may be employed in the treatment of convulsions of children during dentition, given in doses of gr. ss to gr. v, gradually increased to gr. viij, in powder, with a little sugar. It is also combined with carbolic acid, in a fluid form, for capping exposed pulps, being applied in the form of a paste to the exposed surface of the dental pulp. It also forms an ingredient of the zinc-filling materials, and of the celluloid base for artificial teeth. Dr. Edw. Eggleston recommends a combination of oxyphosphate and gutta percha as a filling material for large cavities in proximal surfaces of posterior teeth, extending below gum margin. The cavity is first filled one-third full of gutta percha and completed with the oxyphosphate. It is generally supposed that alkalies, especially ammonia, have more effect in disintegrating oxyphosphate fillings in the mouth than have acids.

Dental Formulae

Oxyphosphate of Zinc Preparation for Filling Teeth

Powder

Zinci oxidi.....partes 200

Silicii (fine powd.) . . partes viij Sodii boratis .... partes iv

Pulv. glass.....partes v

Levigate under water to ensure complete admixture, and dry by evaporation ; then calcine at white heat ; then reduce to powder.

Powder 1495

Liquid

Acidi phosphorici,

Aquae.....q.s. to dissolve and evaporate the solution by aid of heat, until it is of the consistence of glycerine.

Another Formula for the Oxyphosphate Preparation in which simply the calcined oxide of zinc and glacial phosphoric acid are employed, is prepared as follows: -

Liquid 1496

Calcine the oxide of zinc for two hours at a white heat, or until it becomes a hard, yellowish mass ; then pulverize in a mortar, and sieve through fine bolting cloth. For the liquid take 3j of glacial phosphoric acid (German), in crystals, and dissolve in f3j of water, and then evaporate to one-third, on a sand bath.

Oxychloride of Zinc Preparation for Filling Teeth

Powder

Zinci oxidi......gr.xxx

Sodii boracis.....gr.ij

Silicii (fine powd.) . . gr.j. Mix thoroughly and subject to a bright-red heat in a crucible. Then grind this frit to a powder, and mix it with three times its weight of calcined oxide of zinc.

Powder 1497

Liquid

Zinci chloridi (deliq.) . Aquae.......

Liquid 1498Liquid 1499

For Neuralgia of the Head.

Von Niemeyer. Ext. hyoscyami, . Zinci oxidi . . . . aa Signa. - Fiat pill, xj.

Begin with one pill morning and evening, and increase to xx or xxx daily.

Liquid 1500Liquid 1501

For Pulp Devitalization. Dr. Crissman. White oxide of zinc . . . 7/8 Hydrochlorate of Cocaine, crystals of......1/8

Creasote q. s. to make a paste. After removal, apply tannin dissolved in glycerine or alcohol.

Liquid 1502