Packaging in Pharmaceutical Industry: Polyethylene Containers


Packaging plays a crucial role for a pharma product as it helps to retain it’s original form and maintain it’s quality until it is consumed by user. Without suitable packaging the product would be subjected to external elements such as light and moisture which can affect it’s integrity. The selection of the packaging material is based on the type of product being manufactured, therefore all the physical and chemical properties of product as well as packaging material are of utmost importance.

Among various packaging material polyethylene plastics (thermoplastic) are in regular use for certain types of sterile products including infusion, eye drops and injections ready filled into disposable syringes. The plastic pharmaceutical containers are made up of at least one polymer together with additives which is dependent on the composition of the polymer and the method of production. Generally additives include plasticisers, resins, stabilizer, lubricant, antistatic agents, mould release agents.

POLYETHYLENE is a popular organic polymer made up of several monomer units of ethylene which is basically a long chain of carbon and hydrogen atoms. It is the most common form of plastic that is widely used because of the suitable properties.


Depending upon the density the polyethylene is of following types:

Low Density Polyethylene (LDPE)

High Density Polyethylene (HDPE) Medium Density Polyethylene (MDPE)

Linear Low Density Polyethylene (LLDPE)

  • 0.910- 0.940 g/cm3
  • High degree of short and long chain branching
  • Have less stronger inter molecular forces
  • Created by free radical polymerization
  • ≥ 0.941 g/cm3
  • Low degree of branching
  • Stronger inter molecular forces
  • Produced by Zeigler- Natta Catalysis
  • 0.926- 0.946 g/cm3
  • Produced by Zeigler- Natta Catalysis
  • 0.915-0.925 g/cm3
  • Linear polymer with short branches
  • Produced by co polymerization of ethylene with short chains alpha olefins

Basically polyethylene is very flexible, light and tough plastic. It is impermeable to water vapors an do not even deteriorate if exposed to sunlight for considerable amount of time. The LOW DENSITY POLYETHYLENE  are relatively permeable to gases and oxygen which can lead to discoloration or tainting if odorous materials are kept. Also sterilization is difficult because of it’s melting point range which is 110-115 °C and soften at about 90 °C. It is also permeable to certain oils and preservatives. Another disadvantage is that it is charged with static electricity causing dust to accumulate which is overcome by using anti statics during manufacturing or by applying antistatic coatings.

HIGH DENSITY POLYETHYLENE on the other hand have several advantages over low density polyethylene as it is more rigid, handling and filling of containers is easier, have low permeability to gases and low resistance to oils. They have higher melting point (126 °C) due to which it can be sterilized by autoclaving. Due to the higher density it make the material more stiffer and hence could be utilized for creating the opaque bottles by adding certain additives. It gets cracked when it comes in contact with organic solvents therefore requires flouride treatment.


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