Preformulation 1

Question 1

Preformulation Def

Answer 1

R&D stage (1st step; study of physical and chemical properties of a drug molecule. Ensures safe, effective, stable dosage form

Question 2

Examples of Physical Properties

Answer 2

Crystal/Amorphous Form, particle size, shape, solubility

Question 3

Examples of Chemical Properties

Answer 3

Hydrolysis, Oxidation, Reduction and Polymerisation

Question 4

Physicochemical Properties

Answer 4

Solubility, pKa, Partition Coefficent, Oxidation, Hydrolysis, racemization, polymerisation, crystallinity

Question 5

Types of Stability

Answer 5

Microbrial and Temperature

Question 6

Biological property considerations

Answer 6

Oral permeability, bioavailability, site of absorption

Question 7

UV-VIS Spectroscopy Outline

Answer 7

Analystical (quantitative) measure of drug compound. Passing light mainly UV (190-400 nm) through drug

Question 8

Beer Lambert Law

Answer 8

absorbance = (molar extinction coefficent) X (length path in cm) X (concentration)

Question 9

High Performance Liquid Chromatography Outline

Answer 9

Gold standard assay for separation of mixture to understand components physical and chemical properties

Question 10

HPLC Applications

Answer 10

Initial anylate ID & quantification, Impurity Detection, Degradation and Excipient Compatability

Question 11

HPLC Components

Answer 11

Mobile Phase, Stationary Phase, Injector and Detector

Question 12

HLPC Injector Function

Answer 12

Injects sample continuously into flowing mobile phase as it moves through stationary phase

Question 13

HLPC Detector Function

Answer 13

Measure elution time of various components using fluorescence/UV/Refractive Index

Question 14

Size Exclusion Chromatography Outline

Answer 14

Tube contains hollow beads with small openings. Smaller components of mixture passed through are caught in bead, while bigger components pass straight through. Separation based on size

Question 15

HPLC Considerations

Answer 15

Column length, solvent types

Question 16

Solubility Outline

Answer 16

Amount of solute that dissolves in a suitable solvent

Question 17

Preformulation Solubility Studies Aims

Answer 17

solubility of an API in a solvent suitable for it’s delivery

Question 18

Very Soluble Meaning

Answer 18

1g of a substance will dissolves in <1ml of a substance

Question 19

Freely Soluble Meaning

Answer 19

1g of a substance will dissolve in 1-10ml of a solvent

Question 20

Soluble Meaning

Answer 20

1g substance dissolves in 10-30ml solvent

Question 21

Sparingly Soluble Meaning

Answer 21

1g substance 30-100ml solvent

Question 22

Slightly soluble meaning

Answer 22

1g of a substance dissolves in 100-1000ml solvent

Question 23

Very slightly soluble meaning

Answer 23

1g of a substance dissolves in 1000-10,000ml

Question 24

Insoluble meaning

Answer 24

1g of a substance dissolves in 10,000ml

Question 25

What Does Solubility Impact

Answer 25

dissolution rate (low solubility = poor dissolution), dosage (low solubility = lower doses), dosage form (low solubility = no paraenteral)

Question 26

When should a salt form be considered but isn't required)

Answer 26

Freely Soluble

Question 27

When is a salt form required

Answer 27

Insoluble

Question 28

When can salt form not be used

Answer 28

liquid capsules

Question 29

Factors Affecting Solubility

Answer 29

Temp (higher temp = higher solubility), molecular structure (smaller = more soluble), solvent nature, crystal characteristics, pH, common ion effect and solubilising agent

Question 31

Partition Coefficent for Weak Acids

Answer 31

Ka = ([H+][A-])/ [HA]

Question 32

Partition Coefficent for Weak Bases

Answer 32

Kb = [BH+] /([B][H+])

Question 33

pKa for weak acids calculation

Answer 33

pKa = pH - log10(([A-][H+])/[AH])

Question 34

pKa for weak bases calculation

Answer 34

pKa = pH - log10([BH+]/([B][H+]))

Question 35

When are acids ioised

Answer 35

Higher pH

Question 36

When are bases ionised

Answer 36

Lower pH

Question 37

How to increase solubility

Answer 37

create salt, cosolvent and reducing common ion effect (reducing salting out)

Question 38

Partition Coefficent Outline

Answer 38

Measure of lipophilicity indicating relative solubility of drug when compared to solubility in water

Question 39

Why is Partition Coefficent Important

Answer 39

Permeability (lipophilicity), drug absorption in vivo and determination of final formulation

Question 40

Why is Stability Tested at Preformulation

Answer 40

IDs formulation approaches, potential excipients/additives/packaging

Question 41

What is Stability Tested Under

Answer 41

Stability, Hydrolysis, Physical Compression, pH change, oxidation, lysis (UV)

Question 42

Excipients Function

Answer 42

Facilitation of administration, consistent release, increase bioavailability and protect from degradation

Question 43

How are excipient interactions analysed

Answer 43

DSC and HLPC analysis

Question 44

Organoleptic properties Outline

Answer 44

How drugs will by perceived by senses