Drug stability - lecture 4

Question 1

What are the forms of chemical instability ?

Answer 1

Inversion of stereochemistry, geometric isomerism, rearrangement of carbon skeleton, loss of H20 or CO2 (elimination) and chemical interactions (formulation instability)

Question 2

What are enantiomers ?

Answer 2

Enantiomers rotate the plane polarised light by an equal amount an opposite directions - they are optical isomers.

Question 3

What is a racemate ?

Answer 3

An equal mixture of enantiomers.

Question 4

What makes something chiral ?

Answer 4

Structures are chiral is they can not superimposed on their mirror image. if a molecules contains a carbon atom containing 4 different groups. it will not have a plane of symmetry. the carbon atom is the chiral centre.

Question 5

What is racemisation ?

Answer 5

Racemisation involves the inverse of stereochemistry at a chiral centre a 50:50 mixtures of enantiomers which is optically inactive.