Glass is a preferred packaging material for pharmaceuticals due to its protective qualities. It is inert, impervious to air and moisture, and allows inspection of contents. Glass containers come in various sizes and shapes. The manufacturing process involves melting ingredients at high temperatures, shaping the molten glass, annealing to slowly cool, and finishing. There are advantages like inertness and ease of cleaning, and disadvantages like fragility and high cost. Types of glass include Types I-IV which differ in chemical composition and properties suitable for various drug formulations.

1. GLASS AS A PACKAGING MATERIAL
PREPARED BY : AJAY G. HAGE
GUIDE : PROF. R. R. THENGE
DR. RAJENDRA GODE COLLEGE OF PHARMACY MALKAPUR

2. Packaging
 Glass is the preferred packaging material. It is also used in pharmaceutical
industry because it possesses superior protective qualities.
 Glass containers are readily available in a variety of sizes and shapes.
 It is an amorphous, hard, brittle, transparent or translucent .
 having no definite melting point obtained by fusing a mixture of a number of
metallic silicates or borates of sodium, potassium, calcium and lead.

3.  Properties
a) Amorphous
b) Brittle (easily breakable).
c) Transparent or translucent.
d) Good electrical insulator.
e) Unaffected by air, water, acid or
chemical reagents.
f) No definite crystal structure means it has
high compressive strength.
g) Can absorb, transmit and reflect light

4.  Advantages
a) It is inert to most drug products.
b) Impart no odour and taste to the product.
c) Impervious to air and moisture.
d) No change in ageing.
e) FDA approved.
f) It allows easy inspection of the container contents.
g) It can be coloured to protect contents from harmful wavelengths of
light.
h) Easy to clean and sterilize by heat.
i) Containers available in the variety of sizes and shapes.
j) It is recyclable.
There are a few exceptions. For example, glass from light bulbs and
window panes cannot be recycled because they contain ceramics and other
impurities that would contaminate the entire recycling process.

5.  Disadvantages
a) Fragile in nature that produces fragments and .
b) They may crack when subjected to sudden changes in
temperature.
c) Expensive in comparison to plastic.
d) Transportation cost is high because of its heavy weight.
e) Less pressure safety and impact resistance.
f) Special care and protection are required for transportation of glass
containing formulations.
g) Certain types of glasses release alkali into the container contents.

6.  Composition
It is composed primarily of
a) sand,
b) soda ash,
c) limestone,
d) cullet.
Cullet is broken glass that is mixed with the sand, soda ash and limestone to act as a
fusion agent for the entire mixture.
The most common cations found in pharmaceutical glassware are silicon, aluminium,
boron, sodium, potassium, calcium, magnesium, zinc, barium.
The only anion is oxygen.

7. The manufacturing process of glass
Consists of four major operations:
(1) Melting
(2) Shaping
(3) Annealing
(4) Finishing
1. Melting.
The ingredients called batch materials are mixed in the appropriate proportion and heated
to fusion in a furnace. Many designs of glass furnace are in use.
The two most commonly used furnaces are:
(i) Pot furnace and
(ii) Tank furnace.

8.  Pot Furnace.
In this furnace, the charge is fused in fire clay pots. The pots may be opened or closed.
The closed pots are used when the-glass is to be protected from the products of
combustion.
The batch materials are put in the pots. They are placed in a circle inside a furnace and
heated by burning producer gas around them . When the fusion is complete the pots are
removed from the furnace and the fused plastic mass is taken out for shaping.
Pot furnace is employed for the production of high quality glass, since the charge
remains protected from the products of combustion.

10.  Tank Furnace.
It consists of a large rectangular tank built of fire clay blocks.
The batch materials are fed into the tank and producer gas is used as a
fuel in the furnace.
The charge is heated at 1400°- 1500°C for 10-12 hours.

11.  Shaping
The plastic glass formed in the furnace is next shaped or formed into the
desired articles.
It is accomplished by blowing from mouth or by means of a machine. Glass
blowing is a skillful art.
The blowing of a glass into bottle is done as illustrated.
It is elongated under its weight when hung downwards.
The elongated lump is introduced into a mould and is inflated by blowing air
into it from the mouth. On cooling, the bottle is taken out by removing the two-
halves of the mould.

13.  Annealing
It is a process of cooling slowly the newly shaped articles.
If they are cooled quickly they become brittle on account of the
high internal strain.
Annealing is done in a tunnel like oven called lehr.
which is 50 to 60 feet long. At one end the temperature is a little below the
softening point of glass, i.e., 500-600°C and it gradually falls along the length
of the oven.
At the other end the temperature is almost the same as the room temperature.
Immediately after shaping, the articles are introduced into the lehr at the
hotter end and travel towards the cooler end by means of a moving belt.
It takes a few hours for the articles to move along through the tunnel.
Some high quality glasses require long annealing.

14. Finishing.
The articles obtained from the lehr are subjected to a number of
operations such as cleaning, polishing, rounding edges, etc.,
for bringing them to a useable form.
Manufacturing of Glass :- Four basic process
A) Blowing :- It uses compressed air to form the molten glass in to the
cavity of metal mold.
Most commercial bottles & jars are produced.
B) Drawing :- In this method, molten glass is pulled through dies or rollers
that shape the soft glass, rod tubes, sheet glass & other items of uniform diameter
are usually produced by this method.

15. C) Tubing :It has thinner & more uniform wall thickness with
less distortion than blow molded containers. Ampoules,
cartridges and vials drawn from tubing.
D) Pressing & Casting :- In pressing, mechanical force is
used to press the molten glass against the side of mold.
Casting uses gravity or centrifugal force to cause molten
glass to form in the cavity of mold.

16. TYPES OF CONTAINER :-
As per the requirement of the formulation and dosage form, the
different types of container as follows:
1) Light Resistant Container :-
A light resistant container protects the content from the effect light by the specific
properties of material of which it is made. Alternatively, a clear or colorless translucent
container may be made light resistant by means of an opaque (light resistant) covering
and/or stored in dark place.
2) Well Closed Container:-
A well closed container protects the content from extraneous solids and liquids
and from loss of the article under normal condition of handling, shipment storage and
distribution.

17. 3) Tightly Closed Container:-
A tightly closed container protect the content from contamination by
extraneous liquids, solid or vapor from loss of detoriation of the article from
effervescent, evaporation under normal condition of handling, shipment, storage &
distribution.
A tightly closed container must be capable of being tightly reclosed after use
where a tightly closed container is specified as hermetically used for a single dose of an
article. A gas cylinder may be considered to be metallic, tightly closed container
designed to hold the gas under pressure.

18. 4) Hermatically Sealed Container:-
Hermetically sealed container is impervious air or any other gas under normal
condition of handling, shipment, storage & distribution. It may be closed by fusion of
material of the container as in ampoules or may be sealed by appropriate means other
than by fusion of material as in a “Sealed Container” used for a powder for injection.
5) Single Unit Container:-
A single unit container is one that is designed to hold the quantity of a drug
product intended for administration as a single dose or a single finished device intended
for use promptly after the container is opened by other than parental route, direct from
the container. The immediate container and/or outer container or protective packaging is
designed so as to show the evidence of any tampering with the content.

19. 6) Single Dose Container:-
A single dose container is intended for the articles for parentral administration and is
designed to hold a quantity of the drug equivalent to a single dose.
7) Multiple Unit Container:-
Multiple unit container is one that permits withdrawal of successive
portions of the content without changing the strength, quality & purity of the remaining
portion.
8) Multiple Dose Container:-
A multiple dose container is a multiple unit container for articles intended
for parentral administration only.

20. Types of Glasses
These have been categorized as per USP into four different types as.
1. Type I (Highly resistant, Neutral or Borosilicate glass).
2. Type II (Treated soda lime glass).
3. Type III (Soda lime or Regular soda lime glass).
4. Type IV (General purpose soda lime glass).

21. 1. Type I (Highly resistant, Neutral or Borosilicate glass).
This is a type of glass container that contains 80% silica, 10% boric oxide,
small amount of sodium oxide and aluminium oxide.
It is chemically inert and
possess high hydrolytic resistant due to the presence of boric oxide.
It has the lowest coefficient of expansion and so has high thermal shock properties.
Uses of Type I glass containers
Type I glass is suitable as packaging material for most preparations whether parenteral or
non-parenteral, they can also be used to contain strong acids and alkalis

22. 2.Type II glass containers (soda-lime-silica glass/ treated soda-lime glass/
De alkalized soda lime glass)
This is a modified type of Type II glass container with a high hydrolytic
resistance resulting from suitable treatment of the inner surface with sulfur.
This is done to remove leachable oxides and thus prevents blooming/weathering
from bottles.
Type II glass has lower melting point when compared to Type I glass and so
easier to mould.
Uses of Type II glass containers
They are suitable for most acidic and neutral aqueous preparations whether
parenteral or non-parenteral.

23. 3.Type III glass containers (Regular soda lime glass)
This is an untreated soda lime glass with average chemical resistance. It contains 75%
silica, 15% sodium oxide, 10% calcium oxide, small amounts of Aluminium oxide,
magnesium oxide, and potassium oxide.
Aluminium oxide impacts chemical durability while magnesium oxide reduces the
temperature required during moulding.
Uses of Type III glass containers
They are used as packaging material for parenteral products or powders.
They used in packaging non-aqueous preparations and powders for parenteral use with
the exception of freeze-dried preparations.
It is also used in packaging non-parenteral preparations.

24. 4.Type IV glass containers (Type NP glass/General-purpose soda lime glass)
This type of glass container has low hydrolytic resistance.
This type of glass containers are not used for products that need to be
autoclaved as it will increase erosion reaction rate of the glass container.
Uses of type IV glass container
It is used to store topical products and oral dosage forms

25. Glass Containers for Injectible Preparations :- Glass containers intended
for injectable preparations may be ampoules, vials or bottles. The glass of
such container complies with one of the requirement for Hydrolytic
Resistance given below –
Hydrolytic Resistance Test :-
This test is carried on the unused containers. The no. of containers to be
examined & volumes of test solution to be used are given in Table No.1
Nominal Capacity of
Container (ml)
No. of Containers to be
used
Volume of test solution used
for Titration (ml)
5 or Less
5 to 30
More than 30
At least 10
At least 5
At least 3
50
50
100

26. Rinse (wash) each container at least twice with water at room temperature.
Just before test rinse each container with freshly prepared distilled water & fill container
to the brim (Neck). Empty the container & determine average over flow volume.
Fill ampoules with freshly prepared distilled water to maximum volume compatible
with sealing them by fusion of glass & seal them.
Fill bottles or vials to 90% of their over flow volume & cover with borosilicate glass
dishes (petry plate) or aluminum foil previously rinsed with distilled water.
Place the containers in Autoclave; displace air by passage of steam for 10 min.
Raise the temperature from 100˚ to 121˚ over 20 mins., maintain temperature of 121˚
for 60 mins. & reduce from 121˚ to 100˚ over 40 mins.
Remove the containers from the autoclave & cool them in batch of running tap water.

27. Carry out the titration within 1 hour.
.
test liquid
0.15ml of methyl red
50ml of liquid (sample)
0.01M HCl
detection of end point
Titrate freshly prepared distilled water
Blank liquid
add 0.15ml of methyl
red solution
freshly prepared distilled water
0.01M HCl
detection of end point

28. Capacity of container
corresponding to average
overflow volume (ml)
Vol. of 0.01M HCl/100ml of test
solution
Type I or II Glass (ml) Type III Glass (ml)
Not More Than(NMT) 1
More than 1 but NMT 2
More than 2 but NMT 5
More than 5 but NMT 10
More than 10 but NMT 20
More than 20 but NMT 50
More than 50 but NMT 100
More than 100 but NMT 200
More than 200 but NMT 500
2.0
1.8
1.3
1.0
0.80
0.60
0.50
0.40
0.30
0.20
20.0
17.6
13.2
10.2
8.1
6.1
4.8
3.8
2.9
2.2

29. Difference between type I and type II glass:-
Examine the number of container indicated in table 1 rince the container twice with
water and then fill completely with a 4% v/v solution of hydrofluoric acid and allow to
stand at room temperature for 10 minute empty the container and rinse carefully with
water 5 times.
Carry out the procedure describe under hydrolytic resistance. .
Compare the results with limiting values given in table 2 for type I glass the values are
close to type I or type II glass, for type II glass the values are greatly exceed type I or
type II glass are similar to those given for type III glass.

30. Light/spectral transmission-
for coloured glass containers
POWDERED GLASS TEST:-
Rinse thoroughly with water for 6 or more times clean and dry crush the glass and then
grind them and pass through sieve no 20 the weight about 10 gm of powder and transfer to
250ml conical flask and mixed with 30 ml of acetone and then add 50 ml of highly pure
water and keep in autoclave and heat to 121˚C for 30 min.
Reduce the temperature so that the autoclave cools and comes down to atmospheric
pressure in 30 – 45 min. decant the water and add 5 drops of methyl red solution. Titrate
immediately with 0.02 N sulphuric acid.

31. Arsenic release -
Generally this test is carried out for glass ampoules. The inner and outer surface is
washed 5 times with freshly distilled water. Prepare the test solution as describe in the
test for hydrolytic resistant for an adequate number of ampoule to produce 50 ml.
pipette out 10 ml of solution
10 ml of nitric acid
evaporate to dryness on a water bath
oven at 130˚C for 30 min cool
+10ml of hydrazine molybdate reagent
dissolve and heat under reflux
for 20 minutes
Determine the absorbance at about 840nm