L78: Materials 1

Question 1

what are drugs made from?

Answer 1

• API

- Excipient material

Question 2

why is it important to use different solid forms of the same drug?

Answer 2

• alters bioavailability of the drugs (% of drug that enters systemic circulation)
• alters the stability of dosage forms (chemical and physical)
• influences the way in which dosage forms can be processed and manufactured

Question 3

why is bioavailability of a drug important?

Answer 3

• A drug must be in solution before it can cross the gastrointestinal tract wall

Question 4

What is the problem with Identical amount of drug in different physical forms?

Answer 4

may have very different therapeutic effects due to this

Question 5

what is the 2 key importance’s of solid forms?

Answer 5

• stability=dif froms may have dif chemical reactivity

- processing=dif forms have dif flow, compression and water sorption

Question 6

what is the importance of regulatory consideration for solid forms?

Answer 6

• physical form of a drug is an absolute necessity for regulatory approval (European Medicines Evaluation Agency; Food and Drug Administration) due to the safety implications of bioavailability changes
• can patent different forms of an existing drug

Question 7

what is a molecule?

Answer 7

• Distinct entity containing a number of atoms

* Held together by covalent bonds

Question 8

what is a particle?

Answer 8

• A distinct microscopic structure
• Contains millions of molecules
• Held together by non-covalentbonds

Question 9

what is a power?

Answer 9

Visible mass of particles

Question 10

what are the two types of arrangements of molecules?

Answer 10

• crystalline materials

- amorphous materials

Question 11

what is the structure of a crystalline material?

Answer 11

• Ordered, periodic arrangement
• Unit cell repeated in three
dimensions
• Have a melting point

Question 12

what is the structure of amorphous materials?

Answer 12

• No long range order
• Non-random local structure
• Have a glass transition temperature (Tg)

Question 13

What type of crystal are most drugs?

Answer 13

triclinic, monoclinic or orthorhombic

Question 14

what does polymorphism mean?

Answer 14

Different crystal structures of the same compound

Question 15

what are the properties of polymorphism crystals?

Answer 15

they have different melting point and solubilities, but give the sam solution/melt

Question 16

for polymorph stability at a give T and give p which form can be stable?

Answer 16

the one with the lowest free energy (G).

Question 17

what does a monographic relationship mean?

Answer 17

The same form is stable irrespective of temperature

Question 18

what is enantiotropic relationships mean?

Answer 18

either of the two forms can be stable depending on the temperature

Question 19

why is it hard to know whether you have the stable form or not? SLIDE 20

Answer 19

because the metastable form may take a very long time to transform to the stable