To what extent does Initial Shelf Life affect the Potency of Commercial Antacids?

Subject: Chemistry

Supervisor Name: Mrs. Collias

Candidate Name: Joson Thomas

Candidate Number: 000847-0104

Word Count: 3,790

May 2015

Abstract

In this experiment, I have inspected the following research question: “To what extent does initial

shelf life affect the potency of commercial antacids?”

Commercial antacids relieve acid imbalances within the stomach such as heartburn by

neutralizing the acid. Their potency however ranges depending on the molecular composition of

the antacids. The initial potency of a tablet of each of the three commercial antacids, Tums,

Gaviscon, and Acid Controller Complete, was investigated and compared to one another. They

were taken out of their packaging, crushed, and separated into eight sealed bags per antacid.

Over a span of eight days, the initial shelf life was monitored through three controlled

experiments in which 50 milliliters of 0.1 M hydrochloric acid was titrated onto three separate 50

milliliter beakers with 2 grams of one of the three antacids mixed with 200 milliliters of distilled

water. To indicate when the antacid solution turned acidic, a few drops of phenolphthalein was

added to it prior to titration and when it turned from pink to colorless, the amount of

hydrochloric acid used and the pH change were noted.

During the first few days, the charted results indicated that around 3 milliliters of hydrochloric

acid was necessary to neutralize the antacid solutions, but at the conclusion of the experiment,

only around 2 milliliters was necessary to neutralize the solution. This slight change indicates

that removing the antacids from their packaging over a period of time in their initial shelf life has

a small effect on the potency of the antacids. The initial pH of the antacids was 8 but once the

hydrochloric acid was titrated onto it, the pH went down to 3. The initial pH of the antacids was

not very basic as result of the inactive ingredients added for flavoring.

Word Count: 294

Contents Page

Introduction

Acid Imbalances in the Stomach

Commercial Antacids

The Usefulness of a Titration

1

2

3

6

Hypothesis 7

Apparatus 8

Procedure

Synthesis of Antacid Solution

Titrating the Hydrochloric Acid onto the Antacid Solution

9

9

9

Calculations 11

Results and Analysis 13

Conclusion 16

Evaluation

Sources of Error

Limitation

Further Investigation/Unanswered Questions

17

17

17

18

Bibliography 19

Appendix – Raw Data 21

000847-0104 1

Introduction

Commercial antacids are over-the-counter pharmaceutical products that are used to

relieve acid imbalances within the body such as heartburn; they generally help neutralize the

gastric hydrochloric acid and the inhibition of pepsin (Maton). They are accessible at any drug

store or grocery store and can be used without any detrimental side effects. Even though the

utilization of histamine H2 receptors and proton-pump inhibitors have aided in neutralizing acid

imbalances to a great extent, antacids still prove useful by incorporating a simple chemistry

concept in its use (H2 Blockers). When the antacid is ingested, it works with the acid currently in

the stomach as opposed to limiting the production of the acid (Antacids). There are a wide

variety of commercial antacids that consist of bases such as calcium carbonate and magnesium

hydroxide which differ molecularly and are combined with inactive ingredients which ultimately

serve to react with the hydrochloric acid in the stomach; like how a basic substance reacts with

an acid. From a broader scope, the use of antacids are safer and low-risk compared to a proton-

pump inhibitor in which its use can lead to the development of food allergies. Like with all

pharmaceutical drugs and medicine, antacids are packaged air-tight. Once the antacid is opened

from its packaging, it can be subject to changes to its potency over time but normally that would

take a few years. So I began to wonder if any changes would occur to an antacid in a short

amount of time. Yet more specifically, I wanted to know how potent one tablet of an antacid is in

a short amount of time. I knew antacids retained their potency for many years but I contemplated

whether if antacids can lose some of its potency, even if the change is very slight, in its initial

shelf life. As a result, it led me to examining the following research question:

To what extent does initial shelf life affect the potency of commercial antacids?

000847-0104 2

For this particular investigation, Tums, Gaviscon, and Acid Control was tested in a

controlled experiment for their initial shelf life over a period of eight days in order to see if

removing the antacid from its packaging for extended periods of times over these trials will have

any effect on its potency. Throughout the length of this research, the chemical and biological

aspect of antacids will be acknowledged and how they play a role in the reduction of its strength

in general.

Acid Imbalanced in the Body

H2 histamines, proton-pump inhibitors, and antacids would be meaningless without the

excessive presence of high acidic content within the stomach which is diagnosed as Acidity

(Native Remedies). Acid imbalances include heartburn and gastro esophageal reflux disease, and

the body’s overproduction of hydrochloric acid is one of the main causes of the disease. In a

normal abdominal environment, the parietal cells and g-cells of the stomach cooperate to

produce hydrochloric acid which kills bacteria and breaks down the ingested food by denaturing

the proteins (How Stuff Works). The average pH of this acid is about 3 and in order for the

stomach to protect itself from the corrosive acid, the epithelial cells secrete a bicarbonate – rich

alkaline solution coating the mucosa, and this coating is a base which neutralizes the acid content

in the stomach after the food is digested (How Stuff Works). Sometimes acidic problems occur

due to the introduction of certain spicy foods or substance that causes inflammation to the

surrounding alimentary structures. However in other cases, the acidity problems arise when the

parietal cells secrete excess hydrochloric acid to the point where the body’s own mechanism

cannot neutralize it. Additionally, the lower esophageal sphincter inopportunely opening during

digestion allows some of the acid to escape through the stomach. As a result, antacids are

commonly utilized to combat the excess production.

000847-0104 3

Figure 1.1 Gastroesophageal Reflux Disease (MedicineNet).

In relation to the investigation of the potency of antacids over a short period of time, the

antacids are being titrated by 0.1 M hydrochloric acid through a burette which is the same

concentration of the acid secreted by the parietal cells. Despite the slight dip in strength, the

changes in potency derived from the experiment are obviously minimal, and the base would

continue to neutralize the acid.

Commercial Antacids

There are a variety of commercial antacid brands available as over-the-counter drugs or

prescribed drugs. They are orally ingested and react immediately with the stomach’s acid. The

side effects are diminutive and like with other drugs, problems with the antacid arise when it is

taken in excess to the point where, in some cases, the high levels of calcium can cause milk-

alkali syndrome; it is classified as abnormally high levels of calcium in the body, making the

stomach content too alkaline, and can be fatal (Akhtar 2010). All antacids serve the same

purpose to neutralize the acid content in the stomach by raising the pH (Patient):

000847-0104 4

Figure 1.2 How a base in an antacid reacts with the acid content in the stomach (Tulane

University).

As seen in the illustration above, what typically happens when an antacid is ingested is

that the sodium bicarbonate, NaHCO3, enters the stomach and immediately reacts with the

hydrochloric acid to yield carbonic acid which breaks down into water and carbon dioxide while

the sodium and bicarbonate ions are absorbed by the villi of the small intestine (Vivek 2013).

The varying factor of antacids however are the types of bases used. For this experiment,

Tums, Gaviscon, and Acid Controller Complete were used, and their bases were primarily

analyzed. The following table displays the main bases present in the antacids:

000847-0104 5

Table 1.1 List of Antacids Investigated and their Bases

Antacid Base

Tums Extra Strength Calcium Carbonate

Gaviscon Aluminum Hydroxide and Magnesium

Carbonate

Acid Controller Complete Calcium Carbonate and Magnesium Hydroxide

Down to the basic composition, antacids are usually composed of bases and inactive

ingredients such as preservatives and flavoring. But despite the wide array of bases that

neutralizes the acid, only a handful of them can be commonly used by pharmaceutical companies

in the manufacturing of antacids. The main priority for the bases is not only to effectively

neutralize the stomach’s hydrochloric acid, but to also prevent injuries to the mucous membrane

and stomach lining; the primary bases used in antacids are calcium carbonate, aluminum

hydroxide, magnesium carbonate, magnesium hydroxide, sodium bicarbonate, and potassium

bicarbonate (Snyder). So since the active ingredients are bases, antacids never truly expire like

other pharmaceutical drugs which can be harmful to the body but instead, they lose their

potency.

But for this experiment in particular, only 2 grams of a tablet will be evaluated for eight

days in which each of the tablets of the three antacids will be dissolved in distilled water; so

throughout the investigation, a decrease in potency can be attributed to this. The inactive

ingredients on the other hand have been disregarded and the bases were the primary focus of

gauging the antacids potency with the titration. Essentially the antacids were seen as their

000847-0104 6

respective bases and there was fair ratio of the base to the antacid since the solution turned pink

when phenolphthalein was added.

The Usefulness of a Titration

A major aspect throughout this investigation was the method of titration, a procedure in

which a known amount of solute is used to determine the concentration of an unknown solution

(Purdue University). In terms of this experiment however, the solution that was being titrated

onto was already known as well as its concentration. This was an ideal method because the use

of the burette allows for precision when titrating the acid onto the antacid solution in which the

amount of acid used to neutralize the basic solution can be monitored. Indicators, such as

phenolphthalein, greatly help in determining the exact amount of acid used to neutralize the

solution by giving the solution a distinct color when it comes into contact with either the acid or

base and changes color when the pH changes as a result to the addition of the titrant from the

burette (Carboni). The measurements were then able to be carefully marked and analyzed to

indicate any kind of variation in potency. The illustration below best portrays the setup of the

investigation in which the hydrochloric acid was titrated from the burette and a 50 milliliter

beaker was used to contain the antacid solution:

Figure 1.3 Titration setup with the burette filled with solute and the beaker filled with the

solution. (Doc's Chemistry Lesson's)

000847-0104 7

Hypothesis

All antacids will lose their potency over time starting from their creation. Once the air-

tight container is opened, the exposure of the antacids to the outside environment will further

marginally weaken its strength. So in accordance to the research questions, “To what extent does

initial shelf life affect the potency of commercial antacids?”, the potency would decrease very

slightly during its initial shelf life. Within the first eight days, the prolonged removal of the

antacid outside its packaging will cause it to slightly lose its strength. Now since the antacids

will be diluted with distilled water throughout the entire experiment, it is expected that the

potency of the antacid lessen faster that it is supposed as opposed to using different tablets of an

antacid for each of the days. As the days progress, a smaller amount of the acid would be needed

to neutralize the base portrayed by the negative correlation in the graph:

Graph 1.1 This is a hypothesized graph intended to display the predicted negative correlation

between the amount of hydrochloric acid used over eight days.

The hypothesized correlation of the amount of hydrochloric acid needed to nuetralize the antacid solution over eight

days

Days

Hyd

roch

lori

c A

cid

Use

d (m

L)

Even though the burette might not be able to display the precise amount of acid needed, it

is known that the base will still be losing its potency. So the reason behind the slight decrease of

the potency can be likely attributed to the exposure of the tablet to the outside environment.

000847-0104 8

Apparatus

The following materials were used in the experiment over the span of eight days for each

of the three antacids:

Chemicals (per day/all days) (Amount) Equipment

Tums Extra Strength – Orange Cream (1g/8g) (1) Burette (± 1 mL)

Gaviscon (1g/8g) (1) 50 mL (± 5 mL) Beaker

Acid Controller Complete(1g/8g) (1) 100 mL (± 5 mL) Graduated Cylinder

0.1 M Hydrochloric Acid (9 mL/72 mL) (3) 250 mL (± 5 mL) Erlenmeyer Flask and

Rubber Stoppers

Phenolphthalein (15 drops/120 drops) (1) Mortar and Pestle

(1) Electronic Scale

(1) Glass Funnel

(1) Gallon of Distilled Water

(8) pH Strip

(1) Weighing Boat

(1) Tape

(1) Marker

Procedure

000847-0104 9

An antacid solution was prepared for each of the three tablets, Tums, Gaviscon, and Acid

Controller, to use for the eight days. The procedure can be split into two main parts:

Synthesis of Antacid Solution

A single 200 mL antacid solution for each tablet had to be prepared for use over the span

of eight days in order to test for a change in potency of the tablet. For each day, 25 mL of the

solution was used to be titrated on. First, about 2 to 4 tablets of the Tums were crushed using the

mortar and pestle. Next, the weighing boat was weighed on the electronic scale which was then

reset to zero with the weighing boat on it. About 2 grams of the crushed antacid was measured

onto the weighing boat. Afterwards, 200 mL of distilled water was added to the 250 mL

Erlenmeyer flask. The 2 grams of the crushed antacid was then added into the prepared 250 mL

Erlenmeyer flask and sealed with a rubber stopper. The Tum solution was stirred thoroughly

until there was no precipitate present. The solution was ready to be used for each of the eight

days and the same steps were repeated to create the antacid solution for Gaviscon and. Acid

Controller. A piece of tape with the tablet’s commercial name was used to identify each of the

solutions.

Titrating the Hydrochloric Acid onto the Antacid Solution

For each of the eight days, 25 mL of each of the antacid solution were titrated separately

by hydrochloric acid. Prior to pouring out 25 mL of the solution from the Erlenmeyer flask, it

was shook until there was no precipitate present. About 25 mL of the solution was measured

using the 100 mL graduated cylinder and was then transferred into the 50 mL beaker. Soon

afterwards, the pH strip was used to collect the pH of the solution before titration. Next, a few

drops of Phenolphthalein was added to the solution until it turned pink. The burrete was then

prepared by adding 50 mL of 0.1 M hydrochloric acid using the funnel. The 50 mL beaker was

000847-0104 10

situated under the burette after it was prepared. The acid was carefully titrated onto the solution

until it became clear, and the pH and the amount of acid used were recorded. Following the

completion of the titration, the 100 mL graduated cylinder and the 50 mL beaker was thoroughly

rinsed. The same procedure for preparing and conducting the titration of the Tums was used for

Gaviscon and Acid Controller while resetting the amount of acid in the burette back to 50 mL for

each titration. Once the three titrations were complete for the day, the remaining hydrochloric

acid was poured back into its container. The lab was then cleaned and prepared for the next day.

Once the procedure was done and the data was collected for each of the eight days, each of the

three Erlenmeyer flasks that held the antacid solution were empty so they were washed and

cleaned out. All of the lab apparatus were cleaned and organized for future use as well.

Calculations

000847-0104 11

The following reactions and calculations made throughout the course of the investigation

can be seen in the following tables:

Table 1.2 This table shows all of the neutralization Reaction between the antacid solution

and the 0.1 M Hydrochloric acid.

Antacid Bases Neutralization Reaction

Tums Extra Strength

Calcium Carbonate CaCO3(s) + 2 HCl(aq) ----->

CaCl2(aq) + H2O(l) + CO2(g)

Gaviscon

Aluminum Hydroxide Al(OH)3(s) + 3 HCl(aq) ----->

AlCl3(aq) + 3 H2O(l)

Magnesium Carbonate MgCO3(s) + 2 HCl(aq) ----->

MgCl2(aq) + H2O(l) + CO2(g)

Acid Controller Complete

Calcium Carbonate CaCO3(s) + 2 HCl(aq) ----->

CaCl2(aq) + H2O(l) + CO2(g)

Magnesium Hydroxide Mg(OH)2(s) + 2 HCl(aq) -----

> MgCl2(aq) + 2 H2O(l)

Table 1.3 This table shows the moles of antacid used.

000847-0104 12

Antacid Bases Moles Calculations

Tums

Extra

Strength

Calcium

Carbonate 0.0161 2 grams of calcium carbonate1

x1mole

124 grams of calcium carbonate

Gaviscon

Aluminum

Hydroxide

0.0256

2 grams of aluminum hydroxide1

x1 mole

78 grams of aluminum hydroxide

Magnesium

Carbonate

0.0185

2 grams of magnesium carbonate1

x1 mole

108 grams of magnesium carbonate

Acid

Controller

Complete

Calcium

Carbonate

0.0161

2 grams of calcium carbonate1

x1mole

124 grams of calcium carbonate

Magnesium

Hydroxide

0.0343

2 grams of magnesium hydroxide1

x1mole

58.3 grams of magnesium hydroxide

000847-0104 13

Results and Analysis

The results and data of the lab will be interpreted and explained through the course of this

section. As predicted in the hypothesis, the amount of hydrochloric acid used to neutralize the

solution did decrease very slightly. The recorded data was done with accuracy regardless of the

±1 mL error of the burette. Although some of the data remained the same for consecutive days,

the amount of acid used does decrease as seen in the table:

Table 1.2 Results of the amount of hydrochloric acid used to neutralize the solution over eight

days.

Antacid Amount of Hydrochloric Acid used (±1mL)

Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Day 8

Tums

Extra

Strength

2.8 2.8 2.7 2.6 2.6 2.5 2.4 2.4

Gaviscon 2.9 2.8 2.7 2.7 2.6 2.5 2.5 2.4

Acid

Controller

2.3 2.3 2.3 2.3 2.2 2.2 2.1 2.1

000847-0104 14

Additionally, a negative correlation for each of the antacids can be seen based on the results in

the following graphs:

Graph 1.2 The graphed results to display the negative correlation between the amount of

hydrochloric acid used to neutralize Tums over eight days.

0 1 2 3 4 5 6 7 8 92.2

2.4

2.6

2.8

3

The amount of hydrochloric acid needed to nuetralize Tums over eight days

Days

Hydr

ochl

oric

Acid

Use

d (m

L)

Graph 1.3 The graphed results to display the negative correlation between the amount of

hydrochloric acid used to neutralize Gaviscon over eight days.

0 1 2 3 4 5 6 7 8 92.22.32.42.52.62.72.82.9

The amount of hydrochloric acid needed to nuetralize Gaviscon over eight days

Days

Hydr

ochl

oric

Acid

Use

d (m

L)

000847-0104 15

Graph 1.4 The graphed results to display the negative correlation between the amount of

hydrochloric acid used to neutralize Acid Controller over eight days.

0 1 2 3 4 5 6 7 8 92

2.1

2.2

2.3

The amount of hydrochloric acid needed to nuetralize Acid Controller over eight days

Days

Hydr

ochl

oric

Acid

Use

d (m

L)

As seen in the graphs, the amount of acid used was very close for each of the antacids,

especially Tums and Gaviscon in which around 3 milliliters of hydrochloric acid was used to

neutralize them. On the other hand, Acid Controller started with 2.3 milliliters of acid used and

gradually descended to 2.1 milliliters, making it the weakest of the bases whereas Tums and

Gaviscon ended up needing 2.4 milliliters of acid for neutralization. As for all the antacids, the

change was clearly not rapid and stayed consecutive for a few days as highlighted by the

horizontal lines in the negative trend. As for Even though the potency slightly decreased, it was

certainly not enough to alter the pH as it stayed consistent; this data can be found on Table 1.3 as

well as rest of the raw data in Table 1.4 in Appendix: Raw Data.

As stated in the hypothesis, keeping the antacid tablet diluted with water for eight days

did have an impact in the potency because a reaction occurred between the base and the water.

Since the bases are weak, the 2 grams of the tablet did not completely dissociate in the 200

milliliters of water, and the constant exposure of the bases to water in the closed environment

slightly weakened the potency. The daily removal of 25 mL of the antacid from the flask also

attributed to the decreased potency. Had a new antacid tablet been test for each experiment, the

000847-0104 16

decrease in strength would not have been noticeable. The pink color each of the solutions

immediately had when phenolphthalein was added proves that the bases were spread all

throughout the water although they did not dissociate. As a weak base, the reaction that took

place was greatly reversible and the base was present as its own molecules when it was diluted

with the distilled water (Clark). A chemical equation would not properly portray the bases

because they do not dissociate in water and remain as molecules as seen by the calcium

carbonate from Tums and Acid Controller.

Conclusion

As stated before, the following research question was: To what extent does initial shelf

life affect the potency of commercial antacids? Based on the data received from the experiments,

it can be deduced that the shelf life is affected to a very small extent. This is indicative of the

negative correlation seen in each of the graphs, Graph 1.2, Graph 1.3, and Graph 1.4, for the

antacids. All of the graphs have been combined to show how they all displayed a dip in their

potency:

Graph 1.5 The graphed results to display the negative correlations between the amount of

hydrochloric acid used to neutralize each of the three antacids over eight days.

0 1 2 3 4 5 6 7 8 90

0.5

1

1.5

2

2.5

3

3.5

The amount of hydrochloric acid used to neutralize each of the three antacids over eight days

Tums Extra Strength

Gaviscon

Acid Controller Complete

Days

Amou

nt o

f Hyd

roch

loric

Acid

use

d (m

L)

000847-0104 17

Based on the graph, it clearly took a less amount of acid to neutralize Acid Controller and

just around the same amount to neutralize Tums and Gaviscon as stated before. Throughout the

experiment, Acid Controller always kept precipitating and its composition was not soluble in the

water unlike Gaviscon and Tums, therefore making it a less effective antacid. Through the course

of the investigation, 2 grams of the tablet was mixed with 200 milliliters of water and only 25

milliliters of water was taken daily for the 8 days so this can be primarily linked to the decreased

potency.

Evaluation

This section will discuss the accuracy in the conduction of the lab. Even though the

expected results were acquired, there were a couple main aspects that could have been changed

or added in the procedure of the investigation. First, the pH throughout the titration could have

been recorded at an interval of at least 5 milliliters of hydrochloric acid so a pH curve could have

been created to verify that the initial shelf does not affect the potency enough to alter the pH.

Also a separate experiment could have been conducted using 2 grams of each of the antacid per

day as opposed to using the same 2 grams throughout the 8 days so the data of that experiment

can be used to possibly verify that the potency did indeed dip slightly because the same 2 grams

was used for the entire investigation.

Sources of Error

In terms of measuring, the electronic scale, 200 mL Erlenmeyer flask, 100 mL graduated

cylinder, 50 mL beaker, and burette displayed the number as accurately as they can regarding

their own uncertainties; the electronic scale had an error of ±0.5 grams and the Erlenmeyer

Flask, 50 mL beaker, and the burette had an error of ±1 milliliters. Where the error would come

from is pouring out 25 mL of the antacid solution from the Erlenmeyer flask to the 100 mL

000847-0104 18

graduated cylinder in which some of the liquid was spilled. Additionally in some of the trials, the

titration of the hydrochloric acid onto the solution was not stopped exactly at the endpoint where

the solution turns from pink to clear. Although the data could have been rechecked multiple

times the numbers are going to be small and not vary much due to the nature of the investigation

dealing with the potency of antacids.

Limitations

There was no clear limitation in terms of the equipment used and data recorded. The

flasks held the antacid solution with no leakage, the graduated cylinder and beakers were intact,

the electronic scale was responsive, and there was no issue in allowing or stopping the titration

of hydrochloric acid from the burette. The only limitation was not being able to determine what

precisely caused the antacids to lose their potency.

Further Investigation/Unanswered Questions

As mentioned in the Evaluation, further investigation could have been conducted by

collecting data for pH curves and setting up another experiment using 2 grams of antacid tablet

for every day of the experiment. Additionally, an antacid directly from the package could have

been experimented on for its potency for each trial as opposed to leaving the same antacid

diluted in distilled water for eight days; this way, multiple tablets can be tested for a change in

potency instead of one tablet. However the main unanswered question that remains from this

experiment is how exactly the bases lost the potency. Based on observations and the data, it

appeared that the prolonged dilution of the bases in the distilled water was responsible for the

decrease however it was not determined if the problem lied within the bases reacting with the

water or if it was perhaps a fault in the conduction of the lab.

000847-0104 19

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000847-0104 20

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000847-0104 21

Appendix: Raw Data

Table 1.3

Raw Data collected from the titrations throughout the eight days.

Trial (Day)

Antacid Solution

Volume of antacid solution used (+/- .01mL)

pH before titration

pH after titration

Initial burette reading (+/- .01mL)

Final burette reading (+/- .01mL)

1Tums 25.0 8 3 50.0 47.2

Gaviscon 25.0 8 3 50.0 47.1Acid

Controller25.0 8 3 50.0 47.7

2Tums 25.0 8 3 50.0 47.2

Gaviscon 25.0 8 3 50.0 47.2Acid

Controller25.0 8 3 50.0 47.7

3Tums 25.0 8 3 50.0 47.3

Gaviscon 25.0 8 3 50.0 47.3Acid

Controller25.0 8 3 50.0 47.7

4Tums 25.0 8 3 50.0 47.4

Gaviscon 25.0 8 3 50.0 47.3Acid

Controller25.0 8 3 50.0 47.7

5Tums 25.0 8 3 50.0 47.4

Gaviscon 25.0 8 3 50.0 47.4Acid

Controller25.0 8 3 50.0 47.8

6Tums 25.0 8 3 50.0 47.5

Gaviscon 25.0 8 3 50.0 47.5Acid

Controller25.0 8 3 50.0 47.8

7Tums 25.0 8 3 50.0 47.6

Gaviscon 25.0 8 3 50.0 47.5Acid

Controller25.0 8 3 50.0 47.9

8Tums 25.0 8 3 50.0 47.6

Gaviscon 25.0 8 3 50.0 47.6Acid

Controller25.0 8 3 50.0 47.9

000847-0104 22

Table 1.4 Observations throughout the investigations.

Antacid Observations

Tums – Orange Cream

Tablet Pinkish color

Solution before titration Turns cloudy yellow with

precipitate

Solution with

Phenolphthalein

Becomes dark cloudy pink

Solution after titration Turns back to cloudy yellow

Gaviscon

Tablet White color

Solution before titration Turns opaque white

Solution with

Phenolphthalein

Becomes cloudy pink

Solution after titration Turns back to white color

Acid Controller Complete

Tablet Pink color

Solution before titration Turns pink with a little

precipitate

Solution with

Phenolphthalein

Becomes dark pink

Solution after titration Turns back to light pink color