MDM: DS Packaging and stability Flashcards
Why is packaging required?
- Identification
- Provide information
- To protect the product
- For tamper proofing / child resistance
- Compliace
- Explain the terms ‘primary pack’ and ‘secondary pack’ in terms of the purpose and composition.
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Primary packaging – in direct contact with the medicine (e.g. cap, bottle, vile, blister pack)
- Purpose: Child resistant, tamper resistant & evident, protect from environmental degradation factors (temperature, oxygen, light),
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Secondary packaging – contains the primary pack (e.g. carton) and extras e.g. patient leaflet
- Purpose: Protection against mechanical hazards e.g shock, compression, vibration during handling, storage and transport
State the main options available for the packaging of medicines.
- Plastic (Jars & tubes)
- Metal (jars & tubes)
- Glass (jars only)
- Paper
Glass:
- Good moisture protection
- Clear/ amber glass
- Light protect affordable with amber
- Used for exempts or if materials react with plastic
Metal:
- Good moisture protection
- Better moisture protection
- Internal surfaces need lacquered
Plastic:
- Provide some light protection (not as good as metal/ plastic)
- Moisture protection depends on polymer used
- Polyvinyl chloride, PET, PVC
- Extensive testing to ensure no interactions
- Briefly describe the advantages and disadvantages of at least two of the packaging options described above.
Plastics:
Advantages: shatter proof, light, opaque (protect) or clear
Disadvantages: Not as inert or impermeable as glass/ metal, less resistant to heat and light, components of plastic may leach into product
Metal:
Advantages: Mechanically strong, shatter proof, light weight, impermeable to gases and light
Disadvantages: Can interact with pharmaceutical product so surfaces need to be lacquered
- Briefly describe the differences between thermoplastic and thermosetting polymers.
Thermoplastic: At high temperatures thermoplastic polymers melt and become liquid allowing the polymer chains to flow. They can be moulded into a variety of shapes. Softening and reshaping by the application of heat can be repeated multiple times.
Thermoset polymers: can only be shaped once as cross linked polymers can’t flow. Further heating would break bonds and polymer degradation
- State the purpose of paper in the primary packaging of medicines
To form sachets
(Labels)
- Explain the term laminate and what it can be used for.
Made by bonding 2 or more layers of different materials together. Aims to combine the desirable properties of different layers into a single packaging structure. Cost effective as less material needed.
Blister packs, sachets, tubes
- Explain the types of physical instability seen in solid dosage forms on storage.
- Polymorphic change – reduced dissolution
- Change in disintegration time – may affect dissolution
- Change in crushing strength – impact distigration
- Cracking of coating tablets – poor appearance
Briefly describe the process of blister pack integrity testing and state why this type of test is carried out
Empty blister pack placed in colour liquid. Pressure applied for set time. Take out and check pockets to see if liquid inside. Repeat with product inside blisters
- Briefly describe the application of wraparound or rotary labelling.
•container pulls label and it is then rolled or swept onto the container (round containers only).
- State the four types of glass available for use in the packaging of medicines. Explain their specific uses and the main types of interactions which can occur during their use.
- Type I: Used to produce ampoules/ viles for liquid parental products
- Type II: Used for solutions below pH 7. Otherwise oxidases in glass are more likely to leak out
- Type III: Used to package large volumes
- NP: Not for parentals – sodium leach out. Used for large volumes of topical products
- List four limitations of plastics as packaging materials for parenterals.
- Materials in plastic may leach out into product
- Not as impermeable as glass
- Not as resistant to heat/ light
- Liable to undergo stress crack
- Explain the types chemical instability within medicines:
- Hydrolysis.
The breaking of a molecular bond by reaction with water
b.Oxidation.
Increase in number of Oxygen: Hydrogen ratio
- Dimerisation & polymerisation.
Reaction of the drug molecule with another molecule of the same drug can form polymer or dimer. (formulate acidic pH)
- Isomeric change.
Different isomers have differences in toxicity and pharmacological activity.
- Photodegradation.
Molecules that absorb the wavelength of light associated with sunlight are substitutable to light induced degradation
- Chemical incompatibility.
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Explain how each of the following parameters affect the stability of medicines and how these effects may be minimised:
- Temperature.
- Solvents
- Acid and base catalysis
- Ionic strength
- Light
- oxygen.
- Temperature.
- Store in freezer
- Remove need for heat
- Solvents.
- Replace aqueous solvent with non-aqueous to prevent hydrolysis
- Injections of unstable drugs can be formulated as freeze dry powders
- Suspension
- Acid and base catalysis.
Buffer
- Ionic strength.
- Light.
- Tinted glass
- Outer container
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Oxygen.
* See pp
Explain the difference between ‘adsorption’ and ‘absorption’.
- Adsorption – particle adhesion to a surface
- Absorption – particle diffused into bulk phase
