D6- medicine design and manufacturing (liquid medicines) Flashcards
in medicine formulae, percentages can be…
w/w ‘weight in weight’
w/v ‘weight in volume’
v/v ‘volume in volume’
what is the problem with using conical measures with viscous liquids or suspension?
viscous (sticky) liquid or suspension can stick on the conical flask after pouring out
how do you measure viscous liquids?
- Weigh them taking their density into account
→ weight = volume x density - Small amount – use a weighing boat
Large amount – use a beaker - (Rinse the weighing boat/ beaker with vehicle)
what are the dosing instructions for oral liquid medicines
- The 5 ml spoon (or cup) is the standard measure
→ e.g., Take TWO 5 ml spoonfuls THREE times a day - This also means the strength of the
medicine is expressed per 5 ml
how do you administer oral liquid medicines to young children?
- Two sided spoon- the small side contains 2.5 ml each
- Oral syringe- the liquid must be directed towards the inside of the
baby’s cheek
where to prepare solution?
conical measure unless vehicle is thick and viscous
How to prepare a solution medicine?
1) dissolve the solids in a small volume of the vehicle (beaker and glass rod- rinse beaker)
2)add liquids, volatile last to conical flask
* Small volumes – 0.2 to 2ml: use a pipette
* Large volumes – 2ml or more: use a conical measure
* Do not rinse them!
3)make up to volume with vehicle and mix with glass rod
4)pour into bottle, mix, label bottle. Attach spoon if oral use
How do you assess the quality of your solution after making it?
- Any signs of undissolved solids? should not be any
- Are the colour and smell all right?
- Any signs of liquid trails?
issues with preparing a suspension?
1- conical measures are unsuitable
2- undissolved powder and suspending agents form big lumps in the vehicle
How do you prepare a suspension?
using pestle & mortar;
* Allows to disperse insoluble powders in liquid by applying shearing
* Lumps can be broken up
* A smooth dispersion can be formed
Suspensions are made up to volume in a calibrated (or tared) bottle
How to make suspensions up to volume?
-use calibrated bottle, calibrate with water
-measure water in conical flask up to the required volume, put in bottle
-place a label on the bottle indicating the volume needed
-discard water
How to prepare a suspension?
- Step 1: grind, sieve, weigh powders
- Step 2: make a smooth concentrated paste
- Mix the powder by geometric mixing
- Add a small volume of liquid
- Use shearing to make a smooth dispersion
- Step 3: dilute the paste with liquid
- Step 4: pour into calibrated bottle
- Step 5: add other ingredients
- Step 6: make up to volume
How do you create a suspension from crushed tablets?
- Same general method
- You need to crush the tablets!
- Effective but the final suspension does not look uniform
- Many tablet ingredients are not soluble
how do you assess the quality of your suspension?
- Are the colour and smell all right?
- Can it be poured easily?
- Any lumps?
- Any sign of caking?
- Can the particles be easily dispersed by shaking?
