Pharmaceutical Materials

Question 1

Parts of a drug

Answer 1

Active ingredient and excipients

Question 2

Properties of a solid dosage formulation depend on …..

Answer 2

Chemical composition and solid structure of both drugs and excipients

Question 3

What does using a different solid form of the same drug do

Answer 3

Alters the bioavaliability of the drug
Alters the stability of dosage forms
Influence the way in which the dosage forms can be processed and manufactured
Important for the regulatory control of drugs and dosage forms

Question 4

Bioavailability defition

Answer 4

% of dosage that enters the systemic circulation

Question 5

A drug must be in .. before it can cross the GIT wall

Answer 5

Solution

Question 6

Different physical forms may have different:

Answer 6

Stabilities, chemical reactivities, flow, compression and water sorption properties

Question 7

Molecule?

Answer 7

Entity containing a number of atoms held by covalent bonds

Question 8

Particle?

Answer 8

Microscopic structure containing millions of molecules held by non-covalent bonds

Question 9

Powder?

Answer 9

Visible mass of particles

Question 10

Crystalline materials

Answer 10

Ordered, periodic arrangement.

Unit cell repeated in 3D’s

Have a melting point

Question 11

Amorphous materials

Answer 11

No long range order

Non-random local structure

Have a glass transition temperature

Question 12

What do crystal systems do

Answer 12

Reflect symmetry of arrangement of mols in the crystal

Used to identify solid forms of rugs

Most drugs are triclinic, monoclinic or orthorhombic

Question 13

Polymorphism

Answer 13

Different crystal structures of the same compound

Diffent MP and solubility’s but the same solution/melt

Question 14

Polymorph stability

Answer 14

At a given T and P only one form can be stable - the one with the lowest free energy (G)

Question 15

Monotropic relationship

Answer 15

The same form is stable irrespective of temperature

Question 16

Enantiotropic relationship

Answer 16

Either of the 2 forms may be stable depending on the temperature

Question 17

Caffine polymorphisms forms

Answer 17

Form II changes to form I at 140dgrees

Form I then melts at 238degrees

Question 18

Polymorph stability

Answer 18

Difficult to tell wether you have a stable form or not because the metastable form may take a very long time to transform to the stable form

Question 19

Product shelf life`

Answer 19

2-3 years

Drug must remain stable over this period

Question 20

How many Polymorph does a drug have

Answer 20

Depends on how hard you look

Apsirin has 2 and paracetamol has 3 that we know of

Question 21

Crystal formation occurs in consecutive steps:

Answer 21

Supersaturation of solution -> nucleation

Question 22

Crystal growth

Answer 22

Molecules diffuse to crystal surface and attatch to the growin crystal

Question 23

Crystal habit types

Answer 23

The external shape of the crystal

Tabular
Platy
Prismatic
Acicular

Question 24

Changes in crystal habit

Answer 24

Changes in crystal growth conditions can change the habit

Increase in the degree of supersaturation tends to yeild longer needles and thinner plates

Question 25

Polymorph

Answer 25

Internal arrangement of the molecules in the crystal

Question 26

Appearance of crystals with different habits often indicates…..

Answer 26

The presence of Polymorphs but habit and polymorphism are different and may change independently

Question 27

Amorphous solid

Answer 27

Lacks long range order that is characteristic of a crystal.

Internal structure of interconnected blocks.

Question 28

Synthesis of amorphous materials

Answer 28

Rapid cooling

Fast precipitation

High energy milling

Freeze drying

Question 29

Glass transition of amorphous solid

Answer 29

At the glass transition temperature, the amorphous regions experience transition from rigid state to more flexible state making the temperature at the border of the solid state to rubbery state.

Question 30

Amorphous dissolution

Answer 30

Less stable than crystaine so easer to dissolve

Resulting solution is supersaturated

Question 31

Practical implications of amorphous

Answer 31

All amorphous systems will; recrystallise eventually

Question 32

Solvent

Answer 32

the liquid in which the material is dissolved

Question 33

Solvate

Answer 33

crystalline material that contains one or more molecule(s) of the solvent as part of the unit cell structure

Question 34

Hydrate

Answer 34

a solvate where the solvent molecule is water, i.e., water of crystallisation

Question 35

Anhydrous

Answer 35

no water of crystallisation is present

Question 36

Pseudopolymorph

Answer 36

an alternative (bad) term for solvate

Question 37

Solvate formation

Answer 37

Prepared by crystallisation from the solvent in question

Can form unexpectedly when the drug is in contact with a liquid

Question 38

Hydrate Stoichiometry

Answer 38

• Usually highly specific ratios of water to drug, which leads to monohydrate, dihydrate, trihydrate
• A particular drug can have more than one hydrate form
• Channel hydrates tend to be unstable

Question 39

Hydrate properties

Answer 39

Different MP, solubility’s and dissolution rates compared to anhydrous form

Question 40

Hydrate dissolution

Answer 40

Anhydrous = breaking up solid into molecules (endo) and interaction with solvent (exo)

Hydrate = interaction with water already taken place

Question 41

Multi component solid forms

Answer 41

Contain the drug and another molecule or ion

Salt
Solvate
Co-crystals