Internal and external solutions Flashcards
What type of oral solution protects bacterial growth?
Syrup
What type of oral solution is used to make other products such as mixtures and elixirs?
Syrup
What type of oral solution contains alcohol and sugar?
Elixir
What is the role of alcohol in elixir?
dissolve the drug and act as a preservative
What is linctus for?
Coughs
A ______ is used to describe a solution or suspension
Mixture
The range for a very soluble drug is 1 in ___
less than one
A range of 1 in 1 to 1 in 10 indicates a ___________ drug
freely soluble
A soluble drug has a solubility range of 1 in 10 to 1 in ___
30
A range of 1 in 30 to 1 in 100 indicates a ___________ drug
sparingly soluble
A slightly soluble drug has a solubility range of 1 in 100 to 1 in ____
1000
A range of 1 in 1000 to 1 in 10,000 indicates a __________ drug
very slightly soluble
A practically insoluble drug has a solubility range of 1 in _______
more than 10,000
Which factors affect solubility of a drug?
temperature pH molecular structure particle size solvent/cosolvent
What are the advantages of oral solutions?
Easier to swallow - children and elderly
Fast absorption from GI tract
Even mix so don’t need to shake
More stable than suspensions
What are the disadvantages of oral solutions?
Not convenient for patient
Less stable than solids
May taste unpleasant and may be difficult to mask
What is the role of a vehicle?
Solvent which dissolves the drug
What are common vehicles?
Water - most common
Syrup
Alcohol - rarely used as a vehicle for internal use
Which vehicle can be used as a sweetener, preservative and stabiliser?
glycerol
Fructose, sucrose and glucose are ________
sugar sweetners
Sorbitol, mannitol and saccharin are _________
sugar free sweetners
What is the use of antioxidants such as ascorbic acid and citric acid in oral solutions?
stabilisers
Citrates, carbonates and gluconates are common _______
buffers
What factors affect the stability of oral solutions?
bacterial growth
light and heat
hydrolysis of drug
packaging
Solutions are more stable than solids. True or false?
False.
Are antibiotics stable in solution?
No
How many drops does a 1ml solution contain?
20 drops
How can sterility of eye drops be achieved?
preservatives
single use vials
Once opened, eye drops must be discarded ____ days later
28
Adding sodium hydroxide to eye drops affects ______
tonicity - to make eye drops isotonic
Increasing viscosity reduces contact of eye drops with the eye. True or false?
False - increases
Are preservatives in eye drops compatible with contact lenses?
No
Benzalkonium chloride is a __________ that is used in eye drops
preservative
Single dose vials for eye drops are sterilised by ______
autoclaving
Nose sprays cannot be used for systemic effects. True or false?
False
What are the advantages of drops and sprays?
Reduce systemic side effects
Sprays can be used for systemic effects - bypassing first pass metabolism
Drugs can be administered in children
What are the disadvantages of drops and sprays?
Inaccurate dosing of drops and squeezed bottles
Needs manual dexterity
Short shelf life once opened
What is the active ingredient in simple linctus?
Citric acid
Water is the vehicle used in simple linctus. True or false?
False. Syrup is the vehicle
What is chloroform used for in simple linctus?
Preservative
Double strength chloroform is 1ml in _____
20ml
Single strength chloroform is 1ml in _____
40ml
Chloroform spirit is 5ml in 100 ml of _______
alcohol
When do freshly made eye drops expire?
2 weeks
