internal and external solutions Flashcards
what is a solution?
- a homogeneous mixture of 2 more or components resulting in a one phase system, it results in a transparent solution.
- a solute dissolved in a solvent
what do co-solvents do?
aid dissolution if components are not totally soluble in water
what are some examples of co-solvents
glycerol, propylene, glycol, and ethanol
what are factors affecting solubility?
temperature, molecular structure, solvent/co-solvent, particle size, pH
what are the advantages of oral solutions
easier to swallow, absorption from GIT, even mix (no need to shake), more stable than suspensions
what are the disadvantages of oral solutions
not convenient, less stable than solids, may taste unpleasant and may be difficult to mask, accuracy of dosing
what do you use to measure doses less than 5ml?
oral syringe
what is a vehicle?
solvent which dissolves the drug
what can glycerol be used as?
sweetener, stabiliser, preservative, and vehicle
how many drops are there in 1ml of drops?
1ml contains 20 drops
how can you achieve sterility?
preservatives, sterile single use vials
what must packaging do?
protect from contamination and allow accurate dose
what is the expiry date of eye drops?
once opened it must be discarded 28 days later
what can the packaging for eye drops be?
single dose vials, plastic bottles, glass bottles, auto dropper
what are the advantages of drops and sprays
convenient, reduced systemic side effects, local fast effects, sprays can be used for systemic effects bypassing 1st pass metabolism, drops can be administered in children
