Commercial Antacid – Chemistry Project

 

S.No.		Contents	II	Page No.
I.		Introduction		4
II.		Requirements		6
III.		Procedure		7
IV.		Observation		10
V.		Conclusion		13
VI.		Bibliography		13

INTRODUCTION

An Antacid is any substance, generally a base or basic salt, which neutralizes stomach acidity. They are used to relieve acid indigestion, upset stomach, sour stomach, and heartburn.

ACTION MECHANISM

Antacids perform a neutralization reaction, i.e. they buffer gastric acid, raising the pH to reduce acidity in the stomach. When gastric hydrochloric acid reaches the nerves in the gastrointestinal mucosa, they signal pain to the central nervous system. This happens when these nerves are exposed, as in peptic ulcers. The gastric acid may also reach ulcers in the oesophagus or the duodenum.

Other mechanisms may contribute, such as the effect of aluminium ions inhibiting smooth muscle cell contraction and delaying gastric emptying.

INDICATIONS

Antacids are taken by mouth to relieve heartburn, the major symptom of gastro oesophageal reflux disease, or acid indigestion. Treatment with antacids alone is symptomatic and only justified for minor symptoms. Peptic ulcers may require H2-receptor antagonists or proton pump inhibitors.

The utility of many combinations of antacids is not clear, although the combination of magnesium and aluminium salts may prevent alteration of bowel habits.

INTERACTIONS

Altered pH or complex formation may alter the bioavailability of other drugs, such as tetracycline. Urinary excretion of certain drugs may also be affected.

PROBLEMS WITH REDUCED STOMACH ACIDITY

Reduced stomach acidity may result in an impaired ability to digest and absorb certain nutrients, such as iron and the B vitamins. Since the low pH of the stomach normally kills ingested bacteria, antacids increase the vulnerability to infection. It could also result in reduced bioavailability of some drugs. For example, the bioavailability of ketoconazole (antifungal) is reduced at high intragastric pH (low acid content).

SOME FAMOUS ANTACID BRANDS

1. Alka-Seltzer – NaHCO₃ and/or KHCO₃

2. Equate – Al(OH)₃ and Mg(OH)₂

3. Gaviscon – Al(OH)₃

4. Maalox (liquid) – Al(OH)₃ and Mg(OH)₂

5. Maalox (tablet) – CaCO₃

6. Milk of Magnesia – Mg(OH)₂

7. Pepto-Bismol – HOC₆H₄COO

8. Pepto-Bismol Children’s – CaCO₃

9. Rolaids – CaCO₃ and Mg(OH)₂

10. Tums – CaCO₃

11. Mylanta

DRUG NAMES

Some drugs used as antacids are :

1. Aluminium hydroxide

2. Magnesium hydroxide

3. Calcium carbonate

4. Sodium bicarbonate

5. Bismuth subsalicylate

6. Histamine

7. Cimetidine

8. Ranitidine

9. Omeprazole

10. Lansoprazole

REQUIREMENTS :

• Burettes
• Pipettes
• Titration flasks
• Measuring flasks
• Beakers
• Weight box
• Fractional weights
• Sodium hydroxide
• Sodium carbonate
• Hydrochloric acid
• Phenolphthalein.

PROCEDURE :

1. Prepare 1 litre of approximately  HCl solution by diluting 10 ml of the concentrated acid for one litre.

2. Similarly, make 1 litre of approximately NaOH solution by dissolving4.0g of NaOH to prepare one litre of solution.

3. Prepare  Na₂CO₃ solution by weighing exactly 1.325 g of anhydrous sodium carbonate and then dissolving it in water to prepare exactly 0.25 litres (250 ml) of solution.

4. Standardize the HCl solution by titrating it against the standard Na₂CO₃ solution using methyl orange as indicator.

5. Similarly, standardize NaOH solution by titrating it against standardized HCl solution using phenolphthalein as indicator.

6. Powder the various samples of antacid tablets and weigh 1.0 g of each.

7. Add a specific volume of standardised HCl to each of the weighed sample is taken in conical flasks. The acid should be in slight excess, so that it can neutralize all the alkaline component of the tablet.

8. Add 2 drops of phenolphthalein and warm the flask till most of powder dissolves. Filter off the insoluble material.

9. Titrate this solution against the standardised NaOH solution, till a permanent pinkish tinge is obtained. Repeat this experiment with different antacids.

OBSERVATIONS:

Standardisation of HCl solution :

Volume of Na₂CO₃ solution taken = 20.0 ml

S No. of obs.	Burette readings Initial       Final	Volume of acid used
1. 2. 3. 4. 5.	0 ml          15.0 ml 0 ml          15.1 ml 0 ml          15.0 ml 0 ml          15.0 ml 0 ml          15.0ml	15.0 ml 15.1 ml 15.0 ml 15.0 ml 15.0 ml

Concordant volume = 15.0 ml

Applying normality equation,

N₁V₁ = N₂V₂

N₁ * 15.0 =  * 20

Normality of HCl, N₁ = = 0.133 N

Standardisation of NaOH solution :

Volume of the given NaOH solution taken = 20.0 ml

S No. of obs.	Burette readings  Initial     Final	Volume of acid used
1. 2. 3. 4. 5.	0 ml          26.5 ml 0 ml          26.8 ml 0 ml          26.6 ml 0 ml          26.6 ml 0 ml          26.6ml	26.5 ml 26.8 ml 26.6 ml 26.6 ml 26.6 ml

Concordant volume = 26.6 ml

Applying normality equation,

N₁V₁ = N₂V₂

0.133 x26.6 = N₂x20

Normality of NaOH = = 0.176 N

Analysis of antacid tablet :

Weight of antacid tablet powder = 1.0 g

Volume of HCl solution added = 20.0 ml

Antacid	Vol. Of NaOH soln. Used to neutralise unused HCl	Vol. Of HCl soln. Used to neutralise 1.0 g of antacid matter
1. Gelusil 2. Digene 3. Aludrox 4. Logas 5. Ranitidine 6. Ocid 20	12.1 ml 16.0 ml 19.3 ml 24.3 ml 21.4 ml 22.7 ml	12.0 ml 16.2 ml 18.9 ml 24.4 ml 21.7 ml 21.9 ml

CONCLUSION :

The antacid which has maximum volume of HCl is used for neutralizing i.e. Ocid 20 is more effective.

BIBLIOGRAPHY

1. WEBSITES :

• www.pharmaceutical-drugmanufacturers.com

2. BOOKS :

• Comprehensive Practical Manual for class XII
• Pradeep’s New Course Chemistry
• NCERT Class XII Part II

You can find other Chemistry Projects here.