In Manufacturing and use of Antacids
Kelvin Leung
Introduction
Gastric acid, formed in the stomach, is a digestive fluid composed of hydrochloric acid,
potassium chloride, and sodium chloride. The average pH of the gastric acid ranges from 1.33.5. The acid is used to denature ingested proteins, and to activate digestive enzymes needed to
break down the unravelled long chains of amino acids.
To prevent ulcerative conditions, the pH of the acid is often buffered by sodium
bicarbonate, which ensures the pH of the stomach does not drop too low. The secretion of
bicarbonate begins in the pancreas, and can also be found in the duodenum of the intestine.
Along with the buffer, the body also secretes mucous to provide a viscous layer of protection for
the lining of the stomach, against the gastric acid.
Heartburn is the burning sensation in the lower chest, followed with a sour or bitter taste
in the mouth. The feeling is a result of the lower esophageal sphincter’s inability to close
properly. The lower esophageal sphincter (LES) separates the esophagus and the stomach.
When food is ingested, the LES opens, and should close, once an individual has finished eating.
In the case of heartburn, the LES fails to close, and the gastric acid from the stomach is rushed
back into the esophagus.
Antacids are medicines used to counteract and relieve the irritation as a result gastric
acidity. Contrary to the common acid reduce which works to decrease the amount of acid made
in the stomach; antacids are used to neutralize the gastric acid produced by the body. Containing
many basic ingredients, including calcium carbonate, magnesium hydroxide, and sodium
bicarbonate, the medicine is used to provide relief against heartburn and gastritis. Generally,
antacid products are bought without a prescription, and include productions such as Alka-Seltzer,
Mylanta, and Tums.
Le Chatelier’s Principle
Le Chatelier’s Principle states that if a chemical system at equilibrium experiences a
change in concentration, temperature, or volume, the equilibrium will shift to counteract the
change, and a new equilibrium will be established. The overall reaction, being NaHCO3 + HCl
NaCl + H2O + CO2, Le Chatelier’s principle states that if more hydrochloric acid is added in
the equilibrium, the reaction will shift to counteract the addition of the gastric acid.
In Diovol Plus AF (Aluminum Free, Calcium based formula) there is 200mg of calcium
carbonate/ 5mL teaspoon and the recommended adult dosage ranges from 2-4 teaspoons/day
(400-800 mg of calcium carbonate).. It is said to last for up to 4 hours, meaning within the 4
hours, a moderate amount of gastric acid can be released by the body and would have little to no
effect on the pH of the stomach. Of course, the amount and concentration of the acid added into
the equilibrium must be within the range of the amount of antacid ingested to ensure the
equilibrium.
In Manufacturing and use of Antacids
Kelvin Leung
Buffer Solutions
Buffer Solutions contain a week acid/conjugate base mixture, or a weak base/conjugate
acid mixture, and is used to resist changes in pH.
Cells located in the stomach produce sodium bicarbonate as the body’s natural protection
against the acidity of the gastric juices. Sodium bicarbonate is an efficient buffer against many
acids and bases because once completely dissociated into Na+ and HCO3-, the bicarbonate ion
acts as an amphiprotic ion that can become either an acid or a base. By accepting excess protons
or donating protons when it is needed, sodium bicarbonate is able to counteract the effects of
acids and bases added into the solution.
NaHCO3
Na+ + HCO3-
As mentioned before, gastric acid is composed mainly of hydrochloric acid. The chemical
reaction can be broken down in the following equations:
HCl → H+ + ClNaHCO3- → Na+ + HCO3HCO3-
H2CO3 + OH-
Therefore, the hydroxide ions provide a neutralization reaction when mixed with the
hydronium/hydrogen ions.
HCO3- acts as the conjugate base, and the Na+ acts as the salt of a strong base.
Overall Equation: NaHCO3 + HCl
NaCl + H2O + CO2
The Common Ion Effect
The Common Ion effect involves adding an ion to a solution in which the ion is already
present in solution. The equilibrium shifts away from the added ion, as predicted by Le
Chatelier’s Principle.
The addition of bicarbonate ions from antacids shift the equilibrium more to the right, causing a
favouring of products over reactants. By doing so, the resulting pH of the solution within the
stomach will rise due to the neutralization of the hydrochloric acid found in the gastric acid.
HCl + NaHCO3
NaCl + H2CO3
H2CO3 → CO2 + H2O
In Manufacturing and use of Antacids
Kelvin Leung
Works Cited
"Antacids." Internet FAQ Archives - Online Education - Faqs.org. Web. 25 Apr. 2011.
<http://www.faqs.org/health/topics/50/Antacids.html>.
"Heartburn -- Familydoctor.org." Health Information for the Whole Family -- Familydoctor.org.
Web. 25 Apr. 2011.
<http://familydoctor.org/online/famdocen/home/common/digestive/disorders/087.html>.
Wright, Jonathan V. Your Stomach: What Is Really Making You Miserable and What to Do
about It. Mount Jackson, VA: Praktikos, 2009. Print.
"Antacid." Encyclopædia Britannica. Encyclopædia Britannica Online. Encyclopædia
Britannica, 2011. Web. 25 Apr. 2011.
<http://www.britannica.com/EBchecked/topic/26911/antacid>.