Sodii Bicarbonas.Sodium Bicarbonate. NaHco3 = 83. 85. Synonyms. - Baking Soda. Sodium Sesquicarbonate. Soda.

Source

Made from the Carbonate in the same way as the Potassium Bicarbonate is made. Na2Co3 + Co2 + H2O = 2NaHco3. Or by treating Sodium Chloride at the same time with Ammonia gas and Carbon Dioxide. NaC1 + Nh3 + Co2 + H2O = NaHco3 + Nh4c1.

Characters

A white opaque powder, odorless, and having a cooling mildly alkaline taste.

Solubility

In 11.3 parts of water; insoluble in Alcohol and Ether.

Impurities

The carbonate.

Incompatible

It is decomposed by acids and acid salts, e.g., Bismuth Subnitrate.

Sodium Bicarbonate is used to prepare Mistura Rhei et Sodae, Ferri Carbonas Saccharatus, and Pulvis Effervescens Compositus.

Dose, 5 to 60 gr.; .30 to 4.00 gm.

Preparation

Trochisci Sodii Bicarbonatis

Troches of Sodium Bicarbonate. Sodium Bicarbonate, 20; Sugar, 60; Nutmeg, I gm.; Mucilage of Tragacanth, a sufficient quantity to make 100 troches. Triturate the

Nutmeg with the Sugar, gradually added, until they are reduced to a fine powder, and mix this intimately with the Sodium Bicarbonate; then with the Mucilage of Tragacanth, form a mass. Each troche contains 3 gr.; .20 gm., of Sodium Bicarbonate. Dose, 1 to 6 troches.

Action of Sodium Bicarbonate

The same as that of potassium bicarbonate, except that it is much more slowly absorbed from the gastro-intestinal tract, and like all sodium salts it is only feebly depressant. Sodium salts are much less depressant to the cardiac, muscular, and nervous systems, and therefore are far less poisonous than potassium salts.

Therapeutics of Sodium Bicarbonate

External

A lotion of 7 gr. .50 gm. to 1 fl. oz. 30. c.c of water is employed as a sedative to relieve itching. Either in saturated solution or as a fine powder sodium bicarbonate locally applied is the best remedy to relieve the pain from burns. Of late it has been strongly recommended to be used for packing to prevent pain after operations upon the vagina.

Internal

Stomach. - Its use in disease is very similar to that of the corresponding potassium salt, but on account of the two differences just mentioned, it is much more frequently given. Hence it is a very common ingredient of medicines designed to relieve dyspepsia, being taken at or a little before meals to increase the flow of gastric juice, or some time afterwards to neutralize excessive acidity in the cases in which the patient complains of heartburn and acid eructations. Its value is also partly due to its sedative action on the gastric nerves, whereby it relieves gastric pain, and partly also to its power of liquefying tenacious mucus. A very favorite gastric sedative mixture consists of about 10 gr. .60 gm. of sodium bicarbonate, together with the same quantity of bismuth subcarbonate, suspended in mucilage. A grain or two .06 to .12 gm. of sodium bicarbonate with a grain .06 gm. of powdered rhubarb, and some sugar, forms a common stomachic powder for children. Sodium bicarbonate and gentian are also often combined together in stomachic mixtures. Effervescing soda water (made in the same way as potash water, see p. 122) is a mild gastric sedative. In commerce these waters contain neither potash nor soda, but even then the carbon dioxide gas acts as a sedative.

Sodium bicarbonate is so slowly absorbed, and is, in comparison with potassium salts, so poor a solvent of uric acid, that it is rarely used for any effects it may have after absorption. It is stated that large doses (150 to 500 grains 10. to 32. gm.) are useful for diabetic coma.