ACIDIFIERS

Acidifiers

• Acidifers are inorganic chemicals which produce or become acid.

• They increase the level of gastric acid in the stomach when ingested and hence decrease in the pH of the stomach.

• Achlorhydria- patient have deficient secretion of HCl in stomach.

• Systemic acidifier given via injection reduces the alkali reserve in the body and useful in reducing metabolic alkalosis.

TYPES OF ACIDIFIERS:

• Gastric acidifiers, used in controlling pH in stomach.

• Urinary acidifiers, used in controlling pH in urine.

• Systemic acidifiers, used in controlling pH in all the parts of body.

DILUTE HYDROCHLORIC ACID

PREPARATION:

• It is prepared by adding 274 g of concentrated HCl slowly into 726 g of purified water.

• Pungent odour

• Fuming

• It react with metals and releases hydrogen gas.

ASSAY:

• Acidimetry-alkalimetry

• Substance dissolved in water and titrated against sodium hydroxide using methyl red as indicator.

• Neutralization reaction takes place.

• Methyl red indicator is yellow in alkali medium and it changes to red in acid medium.

SODIUM PHOSPHATE DISODIUM HYDROGEN PHOSPHATE DISODIUM HYDROGEN ORTHO PHOSPHATE DECA HYDRATE

PREPARATION:

FROM SODIUM CARBONATE:

• Sodium carbonate is added to the hot solution of phosphoric acid, it gives disodium hydrogen phosphate solution.

• The solution is neutralized concentrated and crystals are separated by centrifugation washed and dried.

FROM CALCIUM PHOSPHATE:

The correct proportions of calcium phosphate and sulphuric acid are reacted to yield mono basic calcium phosphate and calcium sulphate.

• Add boiling water and filtered

• To the filtrate add sodium carbonate to yield the sodium phosphate solution and the dibasic calcium phosphate gets deposited.

• The solution is filtered off and sodium phosphate crystal obtained by concentrating it.

ASSAY:

Acidimetry-alkalimetry

• Substance dissolved in water and titrated against 0.5 N sulphuric acid using bromo cresol green as an indicator.

• The end point is appearance of yellow colour.

• For better end point Bromo cresol green and methyl red mixture is used.

• It gives greenish grey colour.

• It is neutralization reaction.

• The indicator is blue in alkali and changes to yellow in acidic medium.

AMMONIUM CHLORIDE

PREPARATION:

• Commercial

• Neutralization of Ammonia with HCl yields Ammonium chloride.

• The purification is done by sublimation from iron pan.

FROM AMMONIUM SULPHATE:

• By heating ammonium sulphate with sodium chloride.

PREPARATION OF CRUDE AMMONIUM CHLORIDE:

• Ammoniacal gas liquors are treated with lime.

• During this process ammonia gas is liberated which is passed into HCl

• The crude product is commercially known as Sal ammoniac.

ASSAY:

• Substance dissolved in water and to it previously neutralised formaldehyde is added.

• Reason: Formaldehyde may have small amount of formic acid , which must be neutralised before the sodium hydroxide using phenolphthalein.

• Titrated against Sodium hydroxide using phenolphthalein as an indicator

• End point is the appearance of pale permanent pink color.

• In this ammonium chloride undergoes hydrolysis and yield ammonium hydroxide and HCl.

• This reaction is faciliated by formaldehyde by fixing ammonia as hexamine.

• The acid formed is titrated against sodium hydroxide.

• Indicator is colorless in acid and pink in alkaline medium.

IT IS ACIDIMETRY-ALKALIMETRY METHOD- NEUTRALISATION TAKES PLACE:

USE:

• 0.8% w/v solution is isotonic with serum.

• Systemic acidifier

• Diuretic

• Expectorant

• Diaphoretic

• It increases the local irritation which leads to increase the respiratory tract secretions and makes the less viscous mucus.So ammonium chloride and carbonate are used in cough preparation.