Glass is commonly used as a packaging material due to its advantages such as impermeability, clarity, heat resistance allowing for sterilization, and inertness. The main types of glass used are soda lime glass and borosilicate glass. Glass manufacturing involves batching ingredients like silica, lime, and soda then melting, forming, annealing, sorting, and packaging. Forming methods include blow and blow and press and blow processes. Performance tests are conducted to ensure the quality and safety of glass packaging. Regulations govern the submission of data on glass packaging materials and components.

1. Glass as Packaging Material
Dr. Anil Pethe
Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management,
SVKM’S NMIMS, Mumbai

2. • An amorphous inorganic product of fusion that has been cooled to a
rigid condition without crystallizing.
•Not a crystalline solid, not a liquid. It is a “frozen” liquid.
What is Glass?

3. • Type I Neutral (Borosilicate glass)
• Type II Treated Soda lime glass (surface treatment)
• Type III Soda lime glass
• Type IV NP Soda glass (Non-parenteral use)
Types of Glass?

4. Component Percentage
(approx)
Silica (SiO2) 72 %
Lime (CaCO3) 11 %
Soda (NaCO3) 14 %
Alumina (Al2O3) 1.75 %
Potash 0.3 %
General Composition of Glass?

5. • Impermeable to gases, odors, moisture and microorganisms
• Clarity, Transparency
• Because of high M.P. & heat resistance it can be sterilized by dry
or moist heat
• Most inert to all packaging materials
• It can be fabricated to produce variety of shapes
• Due to smooth surface, easy to clean
• Reusable & Recyclable
• Ideal for high speed filling lines
Advantages of Glass?

6. • Heavy
• Susceptible for mechanical breakage
• Unable to withstand sudden changes in temperature
• Leaching of Alkali
• Potential Hazards from glass splinters or fragments in food.
Disadvantages of Glass?

7. Glass Manufacturing

8. • Batching
• Melting
• Forming
• Annealing
• Sorting & Inspection
• Packaging
Glass Manufacturing Steps

9. • It is just like Baking a cake i.e. all ingredients go in and they get mixed
together.
• This is the same for glass container mfg. as all the ingredients mixed
together, and put into shuttle device to bring the raw material to the
Furness.
Batching

10. • Melting of the ingredients occurs in the furnace, which turns the
contents into molten glass.
• This is the cooking process..
• Melting temperature 1550-1600°C
Melting

11. • Two common processes are used
• Blow & Blow process: In this parison is formed by compressed air.
The parison is then transferred into the mold to form specific
shape of the container.
• Press & Blow process: In this method parison I shaped by pressing
the glass against the blank mold with a metal plunger. The parison
is then transferred into the mold to form specific shape of the
container.
Forming

12. • Other processes
• Pressed Glassware: It involve first step of above process & the final
shape is achieved by one pressing of glass which is entrapped &
shaped between mould walls & plunger.
• Tubular Glassware: A tube of glass is first produced &
subsequently cut & shaped (after reheating) by separate process.
Forming

13. Blow and Blow process

14. Press and Blow process

15. • Relatively recent process
• Similar to press & blow process
• More accurately control uniformity of glass distribution
• Weight is reduced upto 25%
Narrow Neck Press & Blow (NNPB)

16. • Slow cooling of the glass in order to strengthen the container.
• Produces a more stable product.
Annealing lehr
(oven) 540 oC
Holding for
15 minutes
Cooling
Almost the softening point
of glass
Annealing Process

17. • Heating to annealing point & then lowering the temp. gradually for
releasing the residual strain in the glass
• Controlled heating & cooling process designed to relieve internal
stress introduced in container during & immediately after glass
container formation.
• Annealing Point: The sp. Temp. in which internal stresses build up
during glass container formation.
Annealing Process

18. • Sorting is carried out either manual or automatic.
• To carryout automatic sorting operations the containers are put onto
a single line conveyer for electronic & mechanical checking i.e. body
dimensions, bore, visual damage etc.
• Manual testing is also performed at lab.
• The sorting area is usually screened from dirtier mfg. process & is
under positive pressure.
Sorting & Inspection

19. • Last part of the production process.
• Glass containers are supplied for many
years in open returnable wooden crates,
but currently used material:
• Fiber board outers
• Shrink wraps
• This is easy for Handling & Transportation.
Packaging

20. • The design involves two basic considerations
• Aesthetic appeal: Consumer convenience.
• Functional efficiency: on Production line, closuring, packing, warehousing &
finally stability at point of sale.
• Design which lead to point to point contact is susceptible to damage
so it should be avoided.
• Design provides a uniform wall section & avoid thick & thin areas.
Design

21. • Large flat surfaces should be avoided as these tend to sink during the
cooling & may give labeling & capacity problems.
• Height of the embossing should be kept minimum (0.4 – 0.75mm)
• A bottle must be designed to be removed from or clear the mould.
• The use of CAD/CAM & computer technology is widely applied to
improve the design
• Stippling of the base is useful in improving base grip, masking mould
scars & improving strength of the container.
Design

22. • Certain decorative process other than labeling
may be used.
• Ceramic Printing
• Thermo-Cal system
• Organic coating and inks
• Inorganic metallic oxide coating
• Colours imparted to Glass
Decoration

23. • Glass containers broadly divided into
• Narrow necked (including sprinkler)
• Wide necked
• Most specialized container names.
• Carboys: exist in balloon shape or cylindrical
or straight side form.
• Cylindrical rounds, Boston rounds: Convential
cylindrical bottle with near flat shoulders
• Winchesters: widely used in UK & covers range from
0.5fl.oz upwards.
Special Pharmaceutical Containers

24. • Tubular glass containers
• Ampoules
• Vials
• Disposable syringes
• Aerosols
Types of containers

25. • Limited use of these containers prior to 1917, but after
introduction of continuously drawing glass tube leads to
greater use.
• Advantages:
• Lower weight,
• Thinner & more even wall control
• Hermitically sealed
Tubular glass containers

26. • The current use of ampoule is vary static.
• It was one of the first unit dose container.
• Some std. are exist for ampoule shapes &
sizes with variations on the neck &
method of opening (scoring & ceramic
point)
• These are sterilized by dry heat or steam
after filling.
Ampoules

27. • These were popular in 1920s & 1930s when first
used.
• These are parallel side containers with a flat or
concave base with variety of neck finishes in various
capacities.
• Injection vials are obtained in either neutral or soda
glass & occasionally in treated soda glass.
• Rubber closure with aluminum over cap used
for multi-dose container
Vials

28. • Use of glass tube with an end cap seal & movable plunger is early
used for unit dose injectable in dental trade.
• The next stage was to combine cartridge tube and syringe thus
creating glass disposable syringe.
• These are also available with two compartments which allow unstable
parts of the pharmaceutical formulation to be kept separate and mix
immediately prior to use.
Disposable syringes

29. • Use of glass offers mixed comments on risk involved.
• Glass offers greater flexibility in design than metal cans.
• Breakage risk can be avoided by adequate bottle
strength plus an external coating of PVC
• Glass bottles cost more than metal cans but offer good
appearance.
• The valves are set in an aluminum over seal.
Aerosols

30. • Due to thermal shock or impact stress
• Can be grouped as:
Critical- hazardous to the user
Major- reduced usability of the container or its contents
Minor- usability of container not affected
• Can be classified as:
Checks
Seams
Non-glass inclusions
Dirt, dope, adhering particles or oil marks
Freaks and malformations
Marks
Glass Defects

31. General Glass Defects

32. Glass Defects

33. • Thermal shock test
• Internal bursting pressure test
• Annealing test
• Vertical load test
• Leakage test
• Autoclaving
• Limit test for alkalinity or chemical resistance
Performance test applied to glass container

34.  The samples are placed in an upright position in a tray which is immersed into hot
water for a given time, then transferred to a cold water bath.
 Temperatures of both baths are closely controlled. Samples are examined before
and after the tests for outside surface cracks or breakage. The amount of thermal
shock a bottle will withstand depends on its size, design and glass distribution.
 Small bottles will probably withstand a temperature differential of 60–80°C, and 1
pint bottles 30–40°C.
 A typical test uses a 45°C temperature difference, hot to cold.
Thermal shock test

35. • The most common instrument is the American Glass Research
increment pressure tester.
• The test bottle is filled with water and then placed inside the test
chamber. A sealing head is applied and the internal pressure
automatically raised by a series of increments. Each increment is held
for a set time.
• The bottle can either be checked to a pre selected pressure level or
the test continued until the container finally bursts.
Internal bursting pressure test

36. • The sample is examined by polarised light in either a polariscope or a strain
viewer.
• The strain pattern is compared against standard strain discs or limit samples.
Normal annealed glassware shows limited strain patterns usually with
colours of red/blue—greater intensities of strain are indicated by colours
ranging from white/orange through red/purple to green, yellow and white.
• Both extremes indicate strain due to either tension or compression. The
interpretation of strain is frequently one of experience.
• When a glass bottle leaves a mould the outside tends to cool more rapidly
than the inside, leaving the inner surface under a state of tension. This strain
is normalised in the lehr, where the whole container is raised to dull red heat
and then cooled slowly.
Annealing test

37. • The bottle is placed between a fixed
platform and a hydraulic ramp platform
which is gradually raised so that a vertical
load is applied.
• The load is registered on a pressure gauge.
Vertical load test

38. • The Food D&C act places a requirement on the manufacturer to
submit data on packaging materials & components to FDA prior to
marketing.
• The same applies for pharmaceuticals under EU legislations.
• Submission must include data on all packaging material constituents
& adequate toxicological studies.
• In UK legislations are similar to USA involving various acts etc.
• Food Labeling Act
• Trade Description Act
• Weights & Measures Act
• The Poison Prevention Packaging Act
Legislations