MAGNESIUM HYDROXIDE SOP
1.0 OBJECTIVE:
To
lay down a procedure of analytical report for the active raw material of the Magnesium hydroxide from the Pharmacopoeia
specifications.
2.0 SCOPE:
This
SOP shall be applicable in Q.C laboratory.
3.0 RESPONSIBILITY:
3.1
Q.C Analysts.
4.0 ACCOUNTABILITY:
4.1
Q.C Manager.
5.0 PROCEDURE:
5.1 Characters:
5.1.1
Appearance:
5.1.1.1
White or almost
white, fine, amorphous powder.
5.1.2
Solubility:
5.1.2.1
Material and equipment:
5.1.2.1.1
Glassware (2 test
tubes, 1 spatula).
5.1.2.1.2
Dilute acid (e.g.
dilute HCl, dilute H2SO4).
5.1.2.1.3
Purified water.
5.1.2.2
Sample:
5.1.2.2.1
Small quantity.
5.1.2.3
Method:
5.1.2.3.1
Take 2 test tubes
and add small quantity of sample for testing solubility according to B.P
specifications.
5.1.2.3.2
Add purified water
in test tube 1 and observe.
5.1.2.3.3
Add dilute acid in
test tube 2 and observe.
5.1.2.4
Observations:
5.1.2.4.1
The sample in test
tube 1 containing with purified water is practically insoluble.
5.1.2.4.2
The sample in test
tube 2 containing with dilute acid is dissolved.
5.2 Identification
tests:
5.2.1
Magnesium
test:
5.2.1.1
Material and equipment:
5.2.1.1.1
Glassware (according
to requirement).
5.2.1.1.2
2.0ml of dilute
nitric acid.
5.2.1.1.3
Dilute sodium
hydroxide.
5.2.1.2
Sample:
5.2.1.2.1
15.0mg.
5.2.1.3
Method:
5.2.1.3.1
Take a test tube
and add 15.0mg of sample in it and add 2.0ml of dilute nitric acid dissolve it.
5.2.1.3.2
And also add
dilute sodium hydroxide to neutralize it.
5.2.1.3.3
Take 2.0ml of this
prescribed solution and add 1.0ml of dilute ammonia.
5.2.1.3.4
A white ppt is
formed.
5.2.1.3.5
Add 1.0ml of
ammonium chloride solution you can observe that ppt has been dissolved.
5.2.1.3.6
Add 1.0ml of
disodium hydrogen phosphate solution.
5.2.1.3.7
Observe the
changes.
5.2.1.4
Observations:
5.2.1.4.1
A white
crystalline ppt is formed.
5.3 Assay:
5.3.1
Apparatus:
5.3.1.1
Glassware
(according to requirement).
5.3.1.2
Analytical
weighing balance.
5.3.1.3
Water bath.
5.3.1.4
Magnetic stirrer.
5.3.1.5
Titration
apparatus.
5.3.2
Material
and reagents:
5.3.2.1
2.0ml of dilute
hydrochloric acid.
5.3.2.2
Purified water
(q.s).
5.3.2.3
10.0ml of ammonium
chloride buffer solution pH=10.
5.3.2.4
50.0mg of mordant
black 11 triturate (as indicator).
5.3.2.5
0.1M sodium edetate.
5.3.3
Sample:
5.3.3.1 0.1g
5.3.4
Method
of analysis:
5.3.4.1 Sample
titration:
5.3.4.1.1
Take a conical
flask and add 0.1g of sample in it.
5.3.4.1.2
Mix it with 20.0ml
of water and 2.0ml of dilute hydrochloric acid by using magnetic stirrer.
5.3.4.1.3
Dilute this
prescribed solution to 300.0ml with purified water.
5.3.4.1.4
Add 10.0ml of
ammonium chloride buffer solution pH 10 and about 50.0mg of mordant black 11
triturate (as indicator) mix it thoroughly.
5.3.4.1.5
Heat it to about
40oC on water bath.
5.3.4.1.6
Set titration
apparatus.
5.3.4.1.7
Titrate with 0.1M sodium
edetate at the same temperature until the colour changes from violet to full
blue.
5.3.4.1.8
Note down the volume
used as shown in Annexure-1.
5.3.4.1.9
And take average.
5.3.4.2 Blank
titration:
5.3.4.2.1
Take a conical
flask and add in it with 20.0ml of water and 2.0ml of dilute hydrochloric acid mix
it by using magnetic stirrer.
5.3.4.2.2
Dilute it to
300.0ml with purified water.
5.3.4.2.3
Add 10.0ml of
ammonium chloride buffer solution pH 10 and about 50.0mg of mordant black 11
triturate (as indicator) mix it thoroughly.
5.3.4.2.4
Heat it to about
40oC on water bath.
5.3.4.2.5
Set titration
apparatus.
5.3.4.2.6
Titrate with 0.1M sodium
edetate at the same temperature until the colour changes from violet to full
blue.
5.3.4.2.7
Note down the
volume used as shown in Annexure-1.
5.3.4.2.8
And take average.
5.3.4.3 Calculate
percentage purity.
5.3.4.4 Calculations:
5.3.4.4.1
After taking
average volume of both blank titration and sample titration. Calculate the
volume used by the examined substance by using formula:
Volume
used by substance = Blank titration - Sample titration.
5.3.4.4.2
For percentage
purity use formula:
%age
purity = volume used by substance x factor x 100
Weight of sample
5.3.4.4.3
Put values and
calculate %age purity.
5.3.5
Factor:
5.3.5.1 1ml
of 0.1M sodium edetate is equivalent to 5.832mg of Mg(OH)2.
5.3.6
Limit:
5.3.6.1
95.0% to 100.5%.
6.0 REVISION LOG:
|
Revision No.
|
Effective Date
|
Reason
|
|
00
|
|
New SOP
|
7.0 REFERENCES:
7.1
The British
Pharmacopoeia. Vol II.,
Official Monograph / Magnesium hydroxide: 2015, pp. 169-170.
8.0 ANNEXURES:
Annexure 1: Assay
observations and calculations (Acid-base titration).
Annexure:
1
Assay
observations and calculations (Acid-base titration)
|
Acid-base titration
Indicator: ___________________
Weight of sample: ____________
Factor: 5.832mg.
Titrant: _____________________
Sample
titration
Average volume: _________________
Blank
titration
Average volume: _________________
Calculations:
Volume
used by substance = Blank titration - Sample titration.
%age
purity = volume used by substance x factor x 100
Weight of sample
RESULT: ____________________________________________________________
|
9.0 ABBREVIATIONS:
|
Abbreviation
|
Expanded Form
|
|
SOP
|
Standard
operating procedure
|
|
&
|
And
|
|
No.
|
Number
|
|
Ltd.
|
Limited
|
|
Sr.#
|
Serial
number
|
|
Q.C
|
Quality
control
|
|
%
|
Percentage
|
|
q.s
|
Quantity
sufficient
|
|
ppt
|
Precipitate
|
|
g
|
Grams
|
|
ml
|
Milliliter
|
|
e.g.
|
For
example
|
|
M
|
Molar
|
|
g/L
|
Grams
per liter
|
|
mg
|
Milligram
|
|
oC
|
Degree
centigrade
|
|
vi
|
Initial
volume
|
|
vf
|
Final
volume
|
|
B.P
|
British
pharmacopoeia
|
|
Vol
|
Volume
|
|
QCA
|
Quality
control active ingredient
|
|
F
|
Format
|