Preparation of Strong ammonium acetate solution I.P

 Aim: To prepare, label and submit 30ml of strong ammonium acetate solution I.P

SYNONYM: Liquor ammonil acetitis fortis

Apparatus required : 

• Beaker
• Glass rod
• Glass funnel
• Test tube
• Measuring cylinder

Formula:

Ingredients	Official Formula	Working Formula
Ammonium bicarbonate	470gm	14.1gm
Glacial acetic acid	453gm(431ml)	13ml
Ammonium solution(Strong)	100ml	3ml
Water up to	1000ml	30ml

Indicators:   Bromothymol blue and Thymol blue

Principle: 

Ammonium acetate is prepared in situ by reacting glacial acetic acid with ammonium bi carbonate. Since the acid is not completely neutralized by ammonium bi carbonate, a second base i.e. strong solution of ammonia is added to complete the neutralization reaction. This makes the preparation alkaline with a pH between 7.6 and 8.1.

CH3COOH + NH4HCO3 → CH4COONH4 + H2O + CO2

NH4OH + CH3COOH → CH3COONH4 + H2O

pH  of the preparation is checked using two indicators namely Bromothymol blue and Thymol blue. Bromothymol blue checks the lower limit and Thymol blue checks the upper pH limit. Solution color at different pH with Bromothymol blue

pH6                        pH7.6

Yellow→  Green            Blue

Thymol blue

pH8               pH9.6

Yellow→  Blue 

Procedure:

• Mix glacial acetic  acid and ammonium bi carbonate with small amount of water
• Add strong ammonia solution 
• Check the pH of the preparation by diluting 1 drop of resulting mixture with 10 drops of water containing one drop of solution of Bromothymol blue or Thymol blue
• Transfer into a previously calibrated bottle using funnel and filter paper
• Make up the volume to the desired level with water
• Label and dispense

Category: Mild expectorant, Diaphoretic(increases sweating therefore is used to reduced elevated body temperature to normal in fever) and Diuretic(increases excretion of water in the form of urine), Expectorant.

Dose: 1-5ml

Storage: Store in a lead free container in cool place (to avoid incompatibility of ammonium acetate with lead otherwise lead acetate will be formed as product of incompatibility).