Antacid IV - 1
Antacid Comparison Laboratory – Instructor’s Version
Developed by: Alex Jannini, David Krause, Heather Malino and Kevin Sweeney,
Rowan University, Department of Chemical Engineering
Edited by: C. Stewart Slater and Mariano Savelski, Rowan University,
Department of Chemical Engineering
Date of Experiment:
OBJECTIVES
Students will perform a back-titration
Students will learn the mechanism of various antacids
Students will gain an understanding of gastric acid and basics of the
digestive system
INTRODUCTION
This experiment is designed to model
the effect of different antacids on gastric
acid. Antacids, a class of medication
typically bought over the counter, are
drugs designed to combat harsh acidic
environments in the stomach that are
associated with ailments such as heart
burn, indigestion, and upset stomach.
Gastric acid is the solution in your
stomach responsible for chemical
digestion of foods. It typically has a pH
of around 1.55 and is comprised of
dilute hydrochloric acid, sodium
chloride, and digestive enzymes.1
When its pH falls too low or the mucus
of the stomach lining wears too thin,
complications typically arise where
antacids are needed.
Since the purpose of this lab is to
measure the amount of HCl neutralized
from the addition of various antacids, it
is not necessary to add the digestive enzymes to the solution. The concentration
of HCl in simulated gastric acid is 0.08 M and the solution also contains 0.2%
(w/v) NaCl. 6.0N HCl is 8.1% wt. HCl and the rest water.1,2 For the purposes of
this lab, a dilute solution of hydrochloric acid is all that is needed.
The aim of this laboratory experiment is to quantify the amount of HCl neutralized
by two different antacids. The active pharmaceutical ingredients (APIs) in
antacids work by either raising the pH and/or by buffering the solution so it is
resistant to further pH change. This lab will deal with antacids that work through
Figure 1. Antacids used in this experiment
