Manufacturing Flashcards
Packaging, Mixing, Comminution, Drying, Quality control, quality assurance
Packaging definition?
Packaging is defined as the collection of different components (packs) which surround the pharmaceutical product from the time of production until its use.
Pack definition?
The pack is necessary for:
- providing life-saving drugs i.e. guarantee stability of the drug
delivering medicines to patients in every imaginable dosage form
e.g. liquid, solid, suspension, drops
Function of a pack?
Containment: the packaging should be designed considering the needs of the product, the manufacturing and the distribution;
Protection: the packaging must protect the product against all adverse external influences e.g. light, moisture, mechanical damage, biological contamination;
Presentation and information: the packaging is essential to show and inform the patient;
Identification, the packaging identity the product;
Convenience, the packaging facilitate the use or administration of the product.
Pack requirements?
Easy to dispose, and preferably:
- -> Made from renewable resources;
- -> Be recycled, or reused;
- -> Reduce pollution (and waste products).
Packaging and quality control considerations on the product side:
- Quality Control (QC) department tests product-pack during manufacturing;
- Quality Assurance (QA) provides all the documents and records related to the product, e.g. starting materials, production, stability.
Packaging and quality control considerations on the sack side:
Package QC is not only performed on the final pack-product combination, BUT also on all the packs used for intermediate products.
Who are the regulatory bodies for packaging and what do they guarantee?
- US, Food & Drug Administration (FDA)
- Europe, European Medicine agency (EMA)
- UK, Medicine & Healthcare Regulatory Agency (MHRA)
Regulatory bodies guarantee that a pack is:
- -> Safe
- -> Efficacious
- -> Perform to the guidelines
Packaging materials requirements:
Inert –> the pack material in contact with the formulation MUST be chemically inactive. This is necessary to preserve the physical and chemical properties of the medicine.
Protect –> the packaging material should guarantee the physical protection and prevent mechanical damages to the medicine, e.g. fracture, cracks.
How is glass produced?
Produced by heating silica, calcium carbonate and sodium carbonate
Classification of different types of glass?
Type I: borosilicate neutral glass – best pharamceutical grade and most inert glass;
Type II: soda lime glass, sulfur dioxide treated surfaces to reduce glass components leaching to the pharmaceutical product;
Type III: soda lime glass, produced to contain large volumes (reduce the surface-to-volume ratio = minimise leaching);
What is Oxygen Transmission Rate?
Plastic is a gas permeable material: level of oxygen influx can be calculated accordingly to the packaging polymer used.
What are laminates?
A laminate is a composite material;
- Laminates are made by layers of different materials, such as paper, plastic and metal;
- Laminates combine different properties in a single packaging material.
- The main advantages of laminates combining aluminium and plastic are:
- -> Mechanical strength;
- -> Light protection;
- ->Moisture protection.
Paper as a packaging material advantages and disadvantages?
Known as one of the oldest pharmaceutical packing, its use is mainly for the secondary pack, as in labels, leaflets, and cartons.
Advantages:
- Low cost and readily available;
- Non-toxic;
- Easily recicled;
- Easily printed.
Disadvantages:
- No barrier properties against moisture, gases and odours;
- Moisture sensitive;
- Poor transparency.
There are different sub-sets of packaging embedded with electronic functionality, these are:
1) Smart packaging: Any packaging that serves a purpose other than containment and protection.
2) Active packaging: Packaging that actively improves the product or its potential use e.g. inhaler
3) Intelligent packaging: A packaging system that transmits or gathers data or information about the product.
What are positive mixtures?
Components mix spontaneously and irreversibly by diffusion (almost perfect mix achieved) e.g. miscible liquids.
- -> No issues in manufacturing processes.
- -> No energy required IF unlimited mixing time.
- ->Input energy required to shorten the mixing time.
What are negative mixtures?
Components that tend to separate and need a constant input energy to maintain the desired dispersion e.g. suspension of solid particles in low viscosity solution.
What are neutral mixtures?
The components have no tendency either to mix or to separate spontaneously.
It is possible to separate the mixture, but energy is required
What is a random mixture?
the components are perfectly mixed, hence the probability of selecting o type of particle is the same in all the positions in the mixture
What is ordered mixing?
- Components are not independent of each other, resulting in a “spontaneous” degree of order in the mix
- It is driven by interactions and cohesive/adhesive forces between components
Why is mixing important?
- Ensure the quality of pharmaceutical products
- Provide even distribution of active component(s) and other ingredients
- Guarantee drug(s) release with the desired rate(s)
- Give even appearance to dosage forms:
- -> Mixture of solids: tablet, capsule, dry powder, etc.
- -> Mixture of liquids: emulsion, cream, etc.
- ->Dispersion of solid particles: paste, suspension
What and how is the scale of scrutiny selected? (How to select testing samples/sample size)
The scale of scrutiny is the amount of material (in weight or in volume) used to test the QUALITY of a mixture.
The proportion of the active component in the dosage form and in the scale of scrutiny is an important factor to determine the quality of a formulation
- -> The lower concentration of active drug in the mixture
- -> The bigger Scale of scrutiny is used
Importance of particle size in mixing:
Particle size of the drug (API) and other excipients (powder form) in the formulation influences:
- Physical performances of the medicine
- Pharmacological effects of the drug
Powders might possess variations in particle size distribution
Segregation is mainly caused by particles differing in:
size, shape, density, and surface properties.
How do size, shape and density exactly influence segregation?
Particle size effects:
- Smaller particles tend to fall through the voids between larger particles
Particle density effects:
- The denser particles tend to move downwards (gravity). IF particles are denser and smaller, the segregation is higher
Particle shape effects:
- Spherical particles are easier to mix, hence segregate more easily than non-spherical particles
- Non-spherical particles have greater surface area to weight ratio: increase cohesive effects
How does segregation occur between manufacturing processes?
Vibration, mechanical forces, gravity
How does segregation occur in an ordered mixture?
This happens when:
- Coarse particles differ in size
- Active sites on coarse particles surface compete with other materials than the fine particles
- Coarse particles are not sufficient to interact with the finer ones
- External mechanical forces (e.g. vibration) reduce the surface attraction energy
The 3 mechanisms of mixing powders?
Convection: macroscopic mixing, relatively quick (extended mixing time is necessary to achieve random mix)
Transfer of large group of particles through the powder bed
Shear: interface mixing
Flows of one ‘layer of material over another ‘layer’, resulting in moving layers at different speeds
Diffusion: allows the movement of individual particles to achieve a true random mix.
Powder bed forced to move: the movement generates space between particles
Tumbling mixers?
- Mix blending granules or free-flowing powders
- Have many different designs
- Might have intermediate containers e.g. feeder for a tablet machine
- Generally rotate about an axis with controlled speed
- Typical powder weight used range from 50g to 100kg
- For best performance, the powder mixture should occupy from ½ to ⅔ of the mixer volume
- Generally used in the blending of excipients prior tableting
- With a correct speed set, shear mixing will occur. With movement the powder dilates, allowing particles to move under gravitational force: diffusive mixing occurs
Mixing of liquids and suspensions:
The same applies to suspensions, with increasing viscosity the mixing:
- Is more “difficult” and take more time
- But, particle sedimentation rate is reduced, hence the suspension is more homogeneous
Methods of mixing liquids:
- Bulk transport: quick degree of mixing
Movement of large amount of material within the mix - Turbulent mixing: highly effective mixing mechanism, volumes forced to move
Constant change in speed and direction; still part move together leaving unmixed volumes - Molecular diffusion: slow diffusion across concentration gradients
Mixing of liquids and suspensions: What are propeller mixers?
Angle blades to promote fluid movement in both axial and radial direction
Formation of vortex (centrifugal forces) is suppressed by:
- Offset angle mounting (A)
- Vertical baffles (B)
Mixing of semi-solids: What are planetary mixers?
- Flowing issues compare to fluids
- High viscous fluids are mixed using the same mixers as semi-solids
- High risk of “dead spot” with non-mixed materials
- Mixers must produce high shear mixing: diffusion mixing cannot occur
How to estimate the variation of the content of a component with respect to the ideal proportion (p, calculated in the total mixture), knowing the sample size (n):
Two are parameters used to describe the variation:
- Standard deviation, SD
- Percentage coefficient of variation, %CV
What is the mixing index?
Compares the content standard deviation from a samples under investigation (SACT) with the one of a fully random mix sample (SR):
The simplest form is M=SR/SACT
Advantage of combining two manufacturing processes in one piece of equipment:(mix and granulate)
No need to transfer the product between processes (reducing segregation associated risks)
How to minimise segregation?
- Similar size of drug and excipients (better with narrow size distribution)
- Use size smaller than 30 um to reduce segregation (but it might cause aggregation)
- Control the shape
- Select components with similar densities
- Granulate the mixture
- Reduce mechanical stresses (e.g. vibration) during the transport between manufacturing processes
- Use equipment for multiple operations e.g. high-speed mixer/granulator for mixing and granulation
- Use of ordered mixtures
Definition of moisture content:
The amount of water contained in a material
%Moisture by volume (MV) is defined as the molecules of water per unit volume by the total number of molecules per unit volume
In case of air, it can be defined as kg of contained water per kg of dry air (water free)
Relative humidity definiton:
Humidity is referred as the amount of water vapour present in the air
–> Relative Humidity (RH), indicates the amount of moisture in the air as a percentage of the maximum amount of moisture that the air can hold (at a specified temperature)
The lower the temperature, the higher is the amount of water vapour that can be held. True or false?
False - the LOWER the temp the higher is the amount of water vapour that can be held
What is the drying process?
- It is (generally) the last and more critical operation in manufacturing pharmaceutical ingredients:
- Drying before packaging ensures quality performances in terms of material processing (intermediate materials, e.g. flowability) and product stability (final product)
- During manufacturing drying is essential to guarantee process performances e.g. granulation, compaction
During drying, moisture content AND temperature can vary due to:
- Evaporation of water from the material to the drying air
- Cooling of drying air to reduce heat-exchange with the material
What is total moisture?
Total moisture is the total amount of water (or liquid phase) associated with a wet solid
TOTAL = FREE + EQUILIBRIUM
What is free moisture content?
the amount of water that can be easily removed e.g. evaporation (aka unbound water)
What is equilibrium moisture content?
The portion of water that is more difficult to be removed
Also known as bound water
Once unbound water is removed, the remaining moisture is in equilibrium with the moisture in the air
What is solute migration?
- Movement of solution in a wet system during drying
- The solute is transported towards the surface, being left where the solvent evaporates
Within solute migration, what are Inter-granular and intragranular migration?
- Inter-granular migration: the solute moves between granules towards the surface
Differences in solute composition between granules - Intra-granular migration: granules are separated during the process
Even distribution of solute within a granule