The document discusses the properties, advantages, and disadvantages of various plastics, highlighting their classifications as thermoplastics and thermosetting types. It emphasizes drug-plastic interactions such as permeation, leaching, and sorption, which can impact the stability and efficacy of pharmaceutical products. Additionally, it outlines tests for evaluating plastic containers, essential for ensuring safety and effectiveness in drug packaging.

1. PACKAGING
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2. Plastics may be defined as any group of substances, of natural or synthetic origins, consisting chiefly of
polymers of high molecular weight that can be moulded into a shape or form by heat and pressure.
Advantages:
• They are light in weight and can be handled easily.
• They are poor conductor of heat.
• They have sufficient mechanical strength.
• They can be transported easily.
• They are unbreakable.
• They are available in various shapes and sizes.
• They are resistant to inorganic chemicals
• They have good protection power.
• There are no chances of formation of flakes.
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PLASTIC

3. Disadvantages:
They are permeable to water vapour and atmospheric gases.
They cannot withstand heat without softening or distorting.
They may interact with certain chemical to cause softening or distortion
They may absorb chemical substances such as preservatives for solution.
They are relatively expensive.
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DISADVANTAGES OF PLASTIC

4. Plastics are classified into two groups according to their behaviour when heated:
1. Thermoplastic type:
This type of plastic gets softened to a viscous fluid on heating and hardens again on cooling. The hardness
after cooling is influenced by the degree of cross linkage or inter-molecular attraction between the long
chain molecules E.g., Polystyrene, polyethylene and polyvinyl chloride.
2. Thermosetting type: this type of plastic may become flexible but does not become fluid on
heating. They are generally hard and brittle at room temperature because of a high degree of cross linking.
They retain their shape even up to the temperature of decomposition. E.g., phenol formaldehyde resins and
urea formaldehyde resin.
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CLASSIFICATION OF PLASTICS:

5. POLYETHYLENE
• This is used as high and low density polyethylene.
• Low density polyethylene (LDPE) is preferred plastic for squeeze bottles.
• Properties: Ease of processing, barrier to moisture, strength/toughness, flexibility, ease of
sealing.
Its melting point being in the range of 110oC to 115oC.
• High density poly ethylene (HDPE) is less permeable to gases and more resistant to oils,
chemicals and solvents.
• Properties: Stiffness, strength / toughness, resistance to chemicals.
• It is widely used in bottles for solid dosage forms.
• Drawback: prone to stress cracking in the presence of surfactants or vegetable or mineral oils.
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COMPOSITION OF PLASTIC

6. POLYSTYRENE
• It is a hard, rigid, light material. It can be easily moulded into any shape. So it is used for preparing
bottles, tubes, jars, boxes and syringes.
• It has low melting point 190oC so cannot be used for hot items or other high temperature
applications.
POLYVINYL CHLORIDE
• Versatility , ease of blending, strength / toughness, resistance to grease/oil, resistance to
chemicals, clarity.
• Used as rigid packaging material and main component of intravenous bags.
• Drawback: Poor impact resistance which can be improved by adding elastomers to the plastics
but it will increase its permeability.
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COMPOSITION OF PLASTIC

7. POLYPROPYLENE:
• It is very much similar to high density polythene. It is very light and heat resistant. Its melting point
is 170oC.
• It can be autoclaved repeatedly. It is used for preparing disposable syringes, tubings, squeeze
bottles and packaging films.
POLYAMIDES (NYLON):
• It is very tough plastic having great amount of flexibility and heat resistance.
• Its melting point is about 200oC.
• It can be autoclaved repeatedly.
• Nylon has electro-negative polar centres and tends to attract several common preservatives such as
phenol, parahydroxy benzoic acid and its esters
• Nylon is used for the preparation of syringes, tubings and packaging films for surgical dressings
and instruments.
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8. POLYCARBONATE:
It is transparent , has high impact strength and very good heat resistance.
It is used in the preparation of surgical equipments.
POLYTETRA FLUOROETHYLENE(PTFE):
It is translucent, opaque and possesses high resistance to solvents and chemicals. It is unchanged even
at a temperature of 250oC.
POLYMETHYL METHOACRYLATE (PMMA):
It is a hard, strong but light, transparent plastic. It softens at about 100oC. it is used for preparing bottles
and tubes.
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COMPOSITION OF PLASTIC

9. Drug- plastic considerations have been divided into five categories:
1. Permeation
2. Leaching
3. Sorption
4. Chemical modification
5. Alteration on the properties of plastics or product
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DRUG –PLASTIC CONSIDERATIONS

10. 1. Permeation
• The transmission of gases, vapours or liquids from the surrounding environment into the plastic container is
known as “Permeation”.
• Permeation of water vapor & oxygen through the plastic wall into the dosage form can be problematic if
the drug is sensitive to hydrolysis and/or oxidation.
• An increase in temperature, increases permeability of gases.
• An increase in crystallinity of the material decreases permeability.
• Hydrophilic plastic materials such as nylon are poor barriers to water vapor, while hydrophobic materials
like polyethylene are better barriers.
• The concentration of drugs in formulations containing volatile ingredients might change when stored in
plastic containers because of the permeation of one or more volatile ingredients through the walls of the plastic
containers.
• Plastic containers also affect the physical properties of the product. For example, when water-in-oil
emulsion is stored in a hydrophobic plastic bottle, there is a tendency for the oil phase to migrate & diffuse into
the plastic.
• Permeation may also affect the shelf-life of a drug.
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DRUG –PLASTIC CONSIDERATIONS

11. 2. Leaching:
• Release of a constituent from the plastic material of the container into the formulation is
known as “leaching”.
• For example, particular dyes which are used as coloring agents may migrate into a product,
contaminates the product and may cause a toxic effect.
3. Sorption:
• The Process of extraction / removal of one or more of the constituents from the formulation by
the packaging material are referred to as “Sorption”.
• Becomes a serious problem particularly for dosage forms that contain drug and/or other
important ingredients in the solution form.
• May significantly affect the therapeutic efficacy of the formulation containing highly potent
drug.
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DRUG –PLASTIC CONSIDERATIONS

12. 4. Chemical reactivity:
• Certain ingredients used in plastic container manufacturing may chemically react with one or
more components of a drug product.
• These chemically incompatible substances may also alter the appearance of the plastic or
formulation.
5. Modification:
• The physical or chemical alteration of the packaging material by the drug product is called
“modification”.
• The content may extract the plasticizer, antioxidant or stabilizer, thus changing the flexibility of
the container.
• Permeation, sorption or leaching may also alter the properties of the plastic container.
• For example:
Oils have a softening effect on polyethylene;
Fluorinated hydrocarbons attack polyethylene & PVC.
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DRUG –PLASTIC CONSIDERATIONS

13. Types of plastic containers:
1. Bottles,
2. containers for semisolid preparations,
3. containers for tablets and capsules,
4. closures.
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TYPES OF CONTAINERS

14. 1) LEAKAGE TEST:
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EVALUATION OF PLASTIC CONTAINERS

15. 2) COLLAPSIBILITY TEST:
This test is applicable to the containers which are to be squeezed for removing the contents.
A container by collapsing inward during use, yield at least 90% of its normal contents at the required
rate of flow at ambient temperature.
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EVALUATION OF PLASTIC CONTAINERS

16. 3) WATER PERMEABILITY TEST FOR PLASTIC CONTAINERS
(INJECTABLE PREPARATIONS IP 1996):
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EVALUATION OF PLASTIC CONTAINERS

17. 4) CLARITY OF AQUEOUS EXTRACT:
• Select unlabelled, unmarked and non-laminated portions from suitable containers, taken at
random. Cut these portions into strips, none of which has a total surface area of 20sq.cm.Wash the strips
free from extraneous matter by shaking them with at least two separate portions of distilled water for
about 30sec. In each case and drain off the water thoroughly.
• Thus, processed sample is taken in to the flask, previously cleaned with chromic acid mixtures
and rinsed with several portions of distilled water and added 250ml distilled water. Cover the flask and
autoclave at 121 C for 30min. Carry out the blank determination using 250ml distilled water. Cool and
⁰
examine the extract, it should be colourless and free from turbidity.
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EVALUATION OF PLASTIC CONTAINERS

18. 5) TRANSPARENCY TEST:
Standard suspension preparation: 1gm hydrazine sulphate in 100ml water and set aside for 6hr. Take 25ml of this solution
and add 25ml of 10%w/v hexamine and stand for 24hr.
Test solution preparation: Sample is prepared by 16-fold dilution of the standard suspension. Fill 5 containers cloudiness
detectable when compared to water filled containers. Absorbance is measured at 640nm and the range is within 0.37 and
0.43.
6) BIOLOGICAL TESTS:
A) Systemic Injection Test:
Test animal – Albino Mice
Inject each of 5 mice in test group with sample or blank observe the animals immediately, again after 4hr & then at 24,
48, 72hrs.
If none of animals shows significant greater biological reactivity than the blank the sample meets the requirements.
Limit- If abnormal behaviour such as Convulsion or Prostration occurs or if body weight loss is greater than 2g, the
sample does not meet the requirements.
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EVALUATION OF PLASTIC CONTAINERS

19. B) INTRA CUTANEOUS TEST:
• Test animal- Rabbit
• Examine the sites of for any tissue reaction like erythema, oedema, neurosis at 24, 48, 72 hours
after injection.
• Limit- difference between the scores of sample and blank should be lesser than 1.0.
C) EYE IRRITATION TEST ON RABBITS:
• Test animal - albino rabbits
• Limit- Sample extract shows no significant irritant response during the observation period with
blank extract.
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EVALUATION OF PLASTIC CONTAINERS

20. Thank You
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