C3g - Batch or continuous? Flashcards
What are batch processes used for and why? (1+3)
to make pharmaceutical drugs
made on demand
usually required or made in smaller quantities
each batch can be controlled for purity
What are continuous processes used for and why? (1+2)
chemicals such as ammonia
needed in large amounts
needed in high demand all year round
What are the advantages of batch processes(2)
flexible - several different products can be made using same equipment - easy to change production to a different product
relative cost of factory equipment are low because less equipment are needed and they are small scale
What are the disadvantages of batch processes(3)
labour-intensive - equipment needs to be set up and manually controlled for each batch and then cleaned out at end - costs a lot
lower rate of production
frequent shut down times
What are the advantages of continuous processes(3)
rare shut down times, production never stops, no time wasted emptying reactor and setting it up again
less labour needed, runs automatically, only interfere if something goes wrong - lower labour costs
quality of product is consistent
What are the disadvantages of continuous processes(2)
high relative costs of equipment/plant
not cost-effective unless it is in constant use
Why is it often expensive to make and develop new pharmaceutical drugs? (5)
labour intensive, larger workforce needed - higher labour costs
a lot of specialised/qualified workers needed to make drugs - higher labour costs
harder to automate when making drugs
a lot of research and testing needed
raw materials rare or expensive to extract from plants
Why is it difficult to test and develop new pharmaceutical drugs that are safe to use? (3)
thousands of compounds are tested to find effective ones
long term trials onhumans are needed to identify possible side effects
stages are expensive, time consuming and ethically controversial
How are chemicals extracted from plant sources? (3)
crushing the plant to break cell walls
boiling it in a suitable solvent to dissolve the compounds
separate chemical by chromatography and identify individual compounds(as spots of different chemicals move up filter paper at different speeds)
How can the purity of a compound be established? (4+2)
measuring MP and BP of drug
- impurities alter MP and BP
- the further the temperature of melting/boiling is from correct one the less pure it is
- pure compounds have definite boiling points
thin layer chromatography
-comparing the speed of movement against a known pure sample
