Powder Technology LAD Flashcards
Outline the steps of how solid dosage forms are manufactured
- Target product profile
- Physico-chemical characterisation of quarantined raw materials: API + excipients
- Powder processing: Milling and Chacterization
- Dosage form specific manufacture
- QC characterisation
what does ‘target product profile’ refer to?
when the “Hit” has been optimised to lead or is in process of lead opimisation, we have to be consiering:
- who the patients are, and
- what the patient population is
- what kind of needs does the px population have
What does physico-chemical characterisation of quarantined raw materials refer to?
API + excipients.
1) Does it have good solubility?
2) Is it amorphous or crystalline in state?
3) Is it labile or stable?
How is this going to work in the patient - target organ? Does it need tp have a prolonged half-life?
What pharmacokinetic profiles would be ideal and what are the economic aspects?
What does powder processing: Milling and Characterisation entail
Mixing, Milling, Flowability
QC Characterisation what does that entail?
Checking for:
- Uniform content
- Uniform weight
- Dosage form specific QC parameters
- Storage stability
what is the purpose of the Quarantining lab?
The Quarantining lab is there to chemicallly + phyiscally identify all material purchased and to be used. Because its OUR responsibility to make sure what has been sent to us has been identified.
So we characterise everything before formulation. Characterisation will indicate purity which is a minimum requirement for patient safety. May also indicate if the drug will be difficult to formulate into a tablet
State the three primary characteristics that affect a powder
Particle Size, Shape and Surface area
why is particle size important in formulating a powder into a tablet?
For a tablet to be made, it may need up to 3-4 different powders with varying shape.
Thats when we go to the processing lab to make the same size and PREVENT areas of high dose quality and low dose quality.
Thus we mill particles to make them smaller in size.
granulation is done to glue particles together into bigger particles.
what is QC and QA
QA/QCdone at the end of the formulation process. It is the combination of quality assurance, that is, the process or set of processes used to measure and assure the quality of a product.
and..
quality control, the process of ensuring products and services meet consumer expectations.
Why is particle surface area affecting
Can affect mixing + how quickly that particle will dissolve in stomach. Dissolution rate will determine how fast drug can be absorbed and therefore onset of action.
what does particle shape affect
content uniformity, mixing and flow
Why is density an issue with powders
density: High density powders = likely to cause segregation/ separation of different constituents.
If you have a suspension, may sediment over time
Why is porosity important
- Some particles have holes and canals. This increases surface area so increases dissolution.
- Porosity influences the ability to compress a powder into a tablet
how are particle sizes calculated
by volume 4/3 * Pi r^3 (volume of a sphere)
What is the problem of particles far from the shape of a perfect sphere
the further the particle is from a perfect sphere the poorer the issues with flow, Because particles with irregular shapes often have greater surfaces areas.
Spheres have low surface areas, so point of contact between eachother is very small. The actual contact area between the spheres is minimal. They flow well with little friction
what do Aciclular particles look like
needle shaped and can cause a lot of friction when together. In general, typically best to get to as close to spherical shape for most, not all formulations, because flow, mixing and handlng is better
what do Angular particles look like
Sharp edged, having a roughly polyhedral shape
what do Dendritic particles look like
Having a branched crystalline shape
what do Fibrous particles look like
Thread like
what do Flaky particles look like
Plate like
what do Granular particles look like
Irregular but of approximately spherical overall form
what do Irregular particles look like
Lacking any symmetry
what do Modular particles look like
having a rounded, irregular shape
Circular, Spherical powders may not make the best suspensions, why?
they have low surface area, so lower resistance. Irregular particles in suspensions orientate themselves round so that they face flat as they sink. Higher resistance.
Powders in air stream
Powdes in air stream are carried by air flow and the particles with high surface area can be ket afloat. Javelin, areodnamic and more able to deposit in the lung
