BY PACKAGING


Plastic Containers

Advantages:

  1. Ease of manufacturing
  2. Available in various types of quality
  3. Freedom of design to which they lend themselves
  4. Extremely resistant to breakage

COMMONLY USED POLYMERS

LESS COMMONLY USED POLYMERS

Polyethylene

Polymethyl methacrylate

Polypropylene

Polyethylene terephthalate

Polyvinyl chloride (PVC)

Polytrifluoroethylene

Polystyrene

Aminoformaldehydes

Polyamides

Dosage Form – Plastic Interactions / Limitations of Plastic Materials:

    1. Permeation
    2. Leaching
    3. Sorption
    4. Chemical modification
    5. Alteration on the properties of plastics or product
  1. Permeation
  • The transmission of gases, vapors 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.
  1. 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.
  1. 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.
  1. 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.
  1.   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: (1) Oils have a softening effect on polyethylene; (2) Fluorinated hydrocarbons attack polyethylene & PVC.