RoA - Solutions Flashcards
Solution advantages
Easy to swallow Easy to manufacture Dose uniformly dissolved Fast onset of action Volume of dose can be measured accurately
Solution disadvantages
Increase drug instability compared to in the solid state
Many drugs poorly soluble in water
Bulky to carry
Some liquids require cold storage to maintain shelf-life
Packaging (higher costs)
Excipients - viscosity enhancers
Improve pouring quality
Excipients - preservatives
Prevent microbial growth
Excipients - sweeteners
Improve palatability of oral solution
Excipients - antioxidants
Improve stability by decreasing oxidation
Excipients - flavouring agent
Mask unpleasant taste of drugs
Excipients - colouring agent
Correlate with flavouring agent
What can other excipients be added for?
Density, isotonicity modifiers
Why is water a good solvent to use?
Lack of toxicity, low cost, pure water used so no dissolved ions
What solvent to use when many drugs aren’t water soluble?
Water but with added miscible liquids
Eg: ethanol, glycerol
What does solubility depend on?
Molecular structure
Particle size
Crystal structure
PKa
How to increase solubility
pH modifier
Co-solvents
What are co solvents used for
For non-ionic drugs where solubility Cannot be adjusted by pH control
What can UV light do to solution
Can decrease solubility so specific packing is used
