Solutions

Question 1

Why is dissolution important

Answer 1

• Absorption in aqueous solution larger particles might form blood clots inject

Question 2

Crystaline structure

Answer 2

• Indavidual drug molecules form a crystaline structure

Question 3

Dissolution

Answer 3

• Energy required to seperate solvent molecule
• Molecules enter the solution when there is a greater
• attraction between drug molecules and solvent molecules than 2 drug molecules

Question 4

Solute-Solvent interactions

Answer 4

• Attractive forces determined by molecular structure of solvent and nature of solvent
• Like dissolves like

Question 5

What causes increase solubiliy

Answer 5

• Different funtional groups is >100x soluable - OH
• Salt formation sodium salt is more soluable
• Highly branched structure and secondary or tertiary alcohol
• Position of -OH on the benzene ring para more ordered to more stable
• Hydrophilic functional groups

Question 6

Choose suspension or solution

Answer 6

• For children dependant on the taste so more likely to eat medicine in suspension than solution (ibuprofin)

Question 7

How would you decrease solubility?

Answer 7

• Addition of hydrophobic groups to structure such as - CL, -F, -CH3,-CH2-

Question 8

Polar solvents

Answer 8

• High permittivity
• Dissolve ionic solutes by reducing ionic attraction between oppositely charged ions in crystaline

Question 9

Permitivity

Answer 9

Measure of the polarisability of a substance when direct curent is applied

Question 10

Semi polar solvents

Answer 10

• Can dissolve polar and non polar substances
• Hydrogen bonding gorup enable polar solvents to dissolve
• Can induce a degree of polarity in non polar solvent molecules

Question 11

Non polar solvents

Answer 11

• Low relative permittivity
• Lack of H-bonding prevents solvents from dissolving ionic and plar solute
• Unable to break covalent bonds
• Dissolves non plar compounds breaks vander waals interactions

Question 12

Temperatures effect solubility

Answer 12

• Dissolution is endothermic so increase in pH causes an increase in solubility
• If exothermic then reverse reaction occours

Question 13

Polymorphs effect on solubility

Answer 13

• Arrangement of polymorphs structure is less stable then solubility is higher (Amorphous structure)